Enum Value

enum Value

Represents any valid JSON value.

See the serde_json::value module documentation for usage examples.

Variants

Null

Represents a JSON null value.

# use serde_json::json;
#
let v = json!(null);
Bool(bool)

Represents a JSON boolean.

# use serde_json::json;
#
let v = json!(true);
Number(Number)

Represents a JSON number, whether integer or floating point.

# use serde_json::json;
#
let v = json!(12.5);
String(alloc::string::String)

Represents a JSON string.

# use serde_json::json;
#
let v = json!("a string");
Array(alloc::vec::Vec<Value>)

Represents a JSON array.

# use serde_json::json;
#
let v = json!(["an", "array"]);
Object(Map<alloc::string::String, Value>)

Represents a JSON object.

By default the map is backed by a BTreeMap. Enable the preserve_order feature of serde_json to use IndexMap instead, which preserves entries in the order they are inserted into the map. In particular, this allows JSON data to be deserialized into a Value and serialized to a string while retaining the order of map keys in the input.

# use serde_json::json;
#
let v = json!({ "an": "object" });

Implementations

impl Value

fn get<I: Index>(self: &Self, index: I) -> Option<&Value>

Index into a JSON array or map. A string index can be used to access a value in a map, and a usize index can be used to access an element of an array.

Returns None if the type of self does not match the type of the index, for example if the index is a string and self is an array or a number. Also returns None if the given key does not exist in the map or the given index is not within the bounds of the array.

# use serde_json::json;
#
let object = json!({ "A": 65, "B": 66, "C": 67 });
assert_eq!(*object.get("A").unwrap(), json!(65));

let array = json!([ "A", "B", "C" ]);
assert_eq!(*array.get(2).unwrap(), json!("C"));

assert_eq!(array.get("A"), None);

Square brackets can also be used to index into a value in a more concise way. This returns Value::Null in cases where get would have returned None.

# use serde_json::json;
#
let object = json!({
    "A": ["a", "á", "à"],
    "B": ["b", ""],
    "C": ["c", "ć", "ć̣", ""],
});
assert_eq!(object["B"][0], json!("b"));

assert_eq!(object["D"], json!(null));
assert_eq!(object[0]["x"]["y"]["z"], json!(null));
fn get_mut<I: Index>(self: &mut Self, index: I) -> Option<&mut Value>

Mutably index into a JSON array or map. A string index can be used to access a value in a map, and a usize index can be used to access an element of an array.

Returns None if the type of self does not match the type of the index, for example if the index is a string and self is an array or a number. Also returns None if the given key does not exist in the map or the given index is not within the bounds of the array.

# use serde_json::json;
#
let mut object = json!({ "A": 65, "B": 66, "C": 67 });
*object.get_mut("A").unwrap() = json!(69);

let mut array = json!([ "A", "B", "C" ]);
*array.get_mut(2).unwrap() = json!("D");
fn is_object(self: &Self) -> bool

Returns true if the Value is an Object. Returns false otherwise.

For any Value on which is_object returns true, as_object and as_object_mut are guaranteed to return the map representation of the object.

# use serde_json::json;
#
let obj = json!({ "a": { "nested": true }, "b": ["an", "array"] });

assert!(obj.is_object());
assert!(obj["a"].is_object());

// array, not an object
assert!(!obj["b"].is_object());
fn as_object(self: &Self) -> Option<&Map<String, Value>>

If the Value is an Object, returns the associated Map. Returns None otherwise.

# use serde_json::json;
#
let v = json!({ "a": { "nested": true }, "b": ["an", "array"] });

// The length of `{"nested": true}` is 1 entry.
assert_eq!(v["a"].as_object().unwrap().len(), 1);

// The array `["an", "array"]` is not an object.
assert_eq!(v["b"].as_object(), None);
fn as_object_mut(self: &mut Self) -> Option<&mut Map<String, Value>>

If the Value is an Object, returns the associated mutable Map. Returns None otherwise.

# use serde_json::json;
#
let mut v = json!({ "a": { "nested": true } });

v["a"].as_object_mut().unwrap().clear();
assert_eq!(v, json!({ "a": {} }));
fn is_array(self: &Self) -> bool

Returns true if the Value is an Array. Returns false otherwise.

For any Value on which is_array returns true, as_array and as_array_mut are guaranteed to return the vector representing the array.

# use serde_json::json;
#
let obj = json!({ "a": ["an", "array"], "b": { "an": "object" } });

assert!(obj["a"].is_array());

// an object, not an array
assert!(!obj["b"].is_array());
fn as_array(self: &Self) -> Option<&Vec<Value>>

If the Value is an Array, returns the associated vector. Returns None otherwise.

# use serde_json::json;
#
let v = json!({ "a": ["an", "array"], "b": { "an": "object" } });

// The length of `["an", "array"]` is 2 elements.
assert_eq!(v["a"].as_array().unwrap().len(), 2);

// The object `{"an": "object"}` is not an array.
assert_eq!(v["b"].as_array(), None);
fn as_array_mut(self: &mut Self) -> Option<&mut Vec<Value>>

If the Value is an Array, returns the associated mutable vector. Returns None otherwise.

# use serde_json::json;
#
let mut v = json!({ "a": ["an", "array"] });

v["a"].as_array_mut().unwrap().clear();
assert_eq!(v, json!({ "a": [] }));
fn is_string(self: &Self) -> bool

Returns true if the Value is a String. Returns false otherwise.

For any Value on which is_string returns true, as_str is guaranteed to return the string slice.

# use serde_json::json;
#
let v = json!({ "a": "some string", "b": false });

assert!(v["a"].is_string());

// The boolean `false` is not a string.
assert!(!v["b"].is_string());
fn as_str(self: &Self) -> Option<&str>

If the Value is a String, returns the associated str. Returns None otherwise.

# use serde_json::json;
#
let v = json!({ "a": "some string", "b": false });

assert_eq!(v["a"].as_str(), Some("some string"));

// The boolean `false` is not a string.
assert_eq!(v["b"].as_str(), None);

// JSON values are printed in JSON representation, so strings are in quotes.
//
//    The value is: "some string"
println!("The value is: {}", v["a"]);

// Rust strings are printed without quotes.
//
//    The value is: some string
println!("The value is: {}", v["a"].as_str().unwrap());
fn is_number(self: &Self) -> bool

Returns true if the Value is a Number. Returns false otherwise.

# use serde_json::json;
#
let v = json!({ "a": 1, "b": "2" });

assert!(v["a"].is_number());

// The string `"2"` is a string, not a number.
assert!(!v["b"].is_number());
fn as_number(self: &Self) -> Option<&Number>

If the Value is a Number, returns the associated Number. Returns None otherwise.

# use serde_json::{json, Number};
#
let v = json!({ "a": 1, "b": 2.2, "c": -3, "d": "4" });

assert_eq!(v["a"].as_number(), Some(&Number::from(1u64)));
assert_eq!(v["b"].as_number(), Some(&Number::from_f64(2.2).unwrap()));
assert_eq!(v["c"].as_number(), Some(&Number::from(-3i64)));

// The string `"4"` is not a number.
assert_eq!(v["d"].as_number(), None);
fn is_i64(self: &Self) -> bool

Returns true if the Value is an integer between i64::MIN and i64::MAX.

For any Value on which is_i64 returns true, as_i64 is guaranteed to return the integer value.

# use serde_json::json;
#
let big = i64::max_value() as u64 + 10;
let v = json!({ "a": 64, "b": big, "c": 256.0 });

assert!(v["a"].is_i64());

// Greater than i64::MAX.
assert!(!v["b"].is_i64());

// Numbers with a decimal point are not considered integers.
assert!(!v["c"].is_i64());
fn is_u64(self: &Self) -> bool

Returns true if the Value is an integer between zero and u64::MAX.

For any Value on which is_u64 returns true, as_u64 is guaranteed to return the integer value.

# use serde_json::json;
#
let v = json!({ "a": 64, "b": -64, "c": 256.0 });

assert!(v["a"].is_u64());

// Negative integer.
assert!(!v["b"].is_u64());

// Numbers with a decimal point are not considered integers.
assert!(!v["c"].is_u64());
fn is_f64(self: &Self) -> bool

Returns true if the Value is a number that can be represented by f64.

For any Value on which is_f64 returns true, as_f64 is guaranteed to return the floating point value.

Currently this function returns true if and only if both is_i64 and is_u64 return false but this is not a guarantee in the future.

# use serde_json::json;
#
let v = json!({ "a": 256.0, "b": 64, "c": -64 });

assert!(v["a"].is_f64());

// Integers.
assert!(!v["b"].is_f64());
assert!(!v["c"].is_f64());
fn as_i64(self: &Self) -> Option<i64>

If the Value is an integer, represent it as i64 if possible. Returns None otherwise.

# use serde_json::json;
#
let big = i64::max_value() as u64 + 10;
let v = json!({ "a": 64, "b": big, "c": 256.0 });

assert_eq!(v["a"].as_i64(), Some(64));
assert_eq!(v["b"].as_i64(), None);
assert_eq!(v["c"].as_i64(), None);
fn as_u64(self: &Self) -> Option<u64>

If the Value is an integer, represent it as u64 if possible. Returns None otherwise.

# use serde_json::json;
#
let v = json!({ "a": 64, "b": -64, "c": 256.0 });

assert_eq!(v["a"].as_u64(), Some(64));
assert_eq!(v["b"].as_u64(), None);
assert_eq!(v["c"].as_u64(), None);
fn as_f64(self: &Self) -> Option<f64>

If the Value is a number, represent it as f64 if possible. Returns None otherwise.

# use serde_json::json;
#
let v = json!({ "a": 256.0, "b": 64, "c": -64 });

assert_eq!(v["a"].as_f64(), Some(256.0));
assert_eq!(v["b"].as_f64(), Some(64.0));
assert_eq!(v["c"].as_f64(), Some(-64.0));
fn is_boolean(self: &Self) -> bool

Returns true if the Value is a Boolean. Returns false otherwise.

For any Value on which is_boolean returns true, as_bool is guaranteed to return the boolean value.

# use serde_json::json;
#
let v = json!({ "a": false, "b": "false" });

assert!(v["a"].is_boolean());

// The string `"false"` is a string, not a boolean.
assert!(!v["b"].is_boolean());
fn as_bool(self: &Self) -> Option<bool>

If the Value is a Boolean, returns the associated bool. Returns None otherwise.

# use serde_json::json;
#
let v = json!({ "a": false, "b": "false" });

assert_eq!(v["a"].as_bool(), Some(false));

// The string `"false"` is a string, not a boolean.
assert_eq!(v["b"].as_bool(), None);
fn is_null(self: &Self) -> bool

Returns true if the Value is a Null. Returns false otherwise.

For any Value on which is_null returns true, as_null is guaranteed to return Some(()).

# use serde_json::json;
#
let v = json!({ "a": null, "b": false });

assert!(v["a"].is_null());

// The boolean `false` is not null.
assert!(!v["b"].is_null());
fn as_null(self: &Self) -> Option<()>

If the Value is a Null, returns (). Returns None otherwise.

# use serde_json::json;
#
let v = json!({ "a": null, "b": false });

assert_eq!(v["a"].as_null(), Some(()));

// The boolean `false` is not null.
assert_eq!(v["b"].as_null(), None);
fn pointer(self: &Self, pointer: &str) -> Option<&Value>

Looks up a value by a JSON Pointer.

JSON Pointer defines a string syntax for identifying a specific value within a JavaScript Object Notation (JSON) document.

A Pointer is a Unicode string with the reference tokens separated by /. Inside tokens / is replaced by ~1 and ~ is replaced by ~0. The addressed value is returned and if there is no such value None is returned.

For more information read RFC6901.

Examples

# use serde_json::json;
#
let data = json!({
    "x": {
        "y": ["z", "zz"]
    }
});

assert_eq!(data.pointer("/x/y/1").unwrap(), &json!("zz"));
assert_eq!(data.pointer("/a/b/c"), None);
fn pointer_mut(self: &mut Self, pointer: &str) -> Option<&mut Value>

Looks up a value by a JSON Pointer and returns a mutable reference to that value.

JSON Pointer defines a string syntax for identifying a specific value within a JavaScript Object Notation (JSON) document.

A Pointer is a Unicode string with the reference tokens separated by /. Inside tokens / is replaced by ~1 and ~ is replaced by ~0. The addressed value is returned and if there is no such value None is returned.

For more information read RFC6901.

Example of Use

use serde_json::Value;

fn main() {
    let s = r#"{"x": 1.0, "y": 2.0}"#;
    let mut value: Value = serde_json::from_str(s).unwrap();

    // Check value using read-only pointer
    assert_eq!(value.pointer("/x"), Some(&1.0.into()));
    // Change value with direct assignment
    *value.pointer_mut("/x").unwrap() = 1.5.into();
    // Check that new value was written
    assert_eq!(value.pointer("/x"), Some(&1.5.into()));
    // Or change the value only if it exists
    value.pointer_mut("/x").map(|v| *v = 1.5.into());

    // "Steal" ownership of a value. Can replace with any valid Value.
    let old_x = value.pointer_mut("/x").map(Value::take).unwrap();
    assert_eq!(old_x, 1.5);
    assert_eq!(value.pointer("/x").unwrap(), &Value::Null);
}
fn take(self: &mut Self) -> Value

Takes the value out of the Value, leaving a Null in its place.

# use serde_json::json;
#
let mut v = json!({ "x": "y" });
assert_eq!(v["x"].take(), json!("y"));
assert_eq!(v, json!({ "x": null }));
fn sort_all_objects(self: &mut Self)

Reorders the entries of all Value::Object nested within this JSON value according to str's usual ordering.

If serde_json's "preserve_order" feature is not enabled, this method does no work because all JSON maps are always kept in a sorted state.

If serde_json's "preserve_order" feature is enabled, this method destroys the original source order or insertion order of the JSON objects in favor of an alphanumerical order that matches how a BTreeMap with the same contents would be ordered.

impl Clone for Value

fn clone(self: &Self) -> Value

impl Debug for Value

fn fmt(self: &Self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result

impl Default for Value

fn default() -> Value

impl Display for Value

fn fmt(self: &Self, f: &mut fmt::Formatter<'_>) -> fmt::Result

Display a JSON value as a string.

# use serde_json::json;
#
let json = json!({ "city": "London", "street": "10 Downing Street" });

// Compact format:
//
// {"city":"London","street":"10 Downing Street"}
let compact = format!("{}", json);
assert_eq!(compact,
    "{\"city\":\"London\",\"street\":\"10 Downing Street\"}");

// Pretty format:
//
// {
//   "city": "London",
//   "street": "10 Downing Street"
// }
let pretty = format!("{:#}", json);
assert_eq!(pretty,
    "{\n  \"city\": \"London\",\n  \"street\": \"10 Downing Street\"\n}");

impl Eq for Value

impl Freeze for Value

impl From for Value

fn from(n: u32) -> Self

impl From for Value

fn from(n: i8) -> Self

impl From for Value

fn from(n: u16) -> Self

impl From for Value

fn from(n: u8) -> Self

impl From for Value

fn from(n: isize) -> Self

impl From for Value

fn from(n: i64) -> Self

impl From for Value

fn from(n: usize) -> Self

impl From for Value

fn from(n: i32) -> Self

impl From for Value

fn from(n: u64) -> Self

impl From for Value

fn from(n: i16) -> Self

impl From for super::Value

fn from(f: String) -> Self

Convert String to Value::String.

Examples

use serde_json::Value;

let s: String = "lorem".to_owned();
let x: Value = s.into();

impl From for super::Value

fn from(f: bool) -> Self

Convert boolean to Value::Bool.

Examples

use serde_json::Value;

let b = false;
let x: Value = b.into();

impl From for super::Value

fn from(f: Map<String, Value>) -> Self

Convert map (with string keys) to Value::Object.

Examples

use serde_json::{Map, Value};

let mut m = Map::new();
m.insert("Lorem".to_owned(), "ipsum".into());
let x: Value = m.into();

impl From for super::Value

fn from(f: f64) -> Self

Convert 64-bit floating point number to Value::Number, or Value::Null if infinite or NaN.

Examples

use serde_json::Value;

let f: f64 = 13.37;
let x: Value = f.into();

impl From for super::Value

fn from(f: f32) -> Self

Convert 32-bit floating point number to Value::Number, or Value::Null if infinite or NaN.

Examples

use serde_json::Value;

let f: f32 = 13.37;
let x: Value = f.into();

impl From for super::Value

fn from(f: &str) -> Self

Convert string slice to Value::String.

Examples

use serde_json::Value;

let s: &str = "lorem";
let x: Value = s.into();

impl From for super::Value

fn from(f: Number) -> Self

Convert Number to Value::Number.

Examples

use serde_json::{Number, Value};

let n = Number::from(7);
let x: Value = n.into();

impl From for super::Value

fn from((): ()) -> Self

Convert () to Value::Null.

Examples

use serde_json::Value;

let u = ();
let x: Value = u.into();

impl FromStr for crate::value::Value

fn from_str(s: &str) -> Result<Value, Error>

impl Hash for Value

fn hash<__H: $crate::hash::Hasher>(self: &Self, state: &mut __H)

impl PartialEq for Value

fn eq(self: &Self, other: &i16) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &isize) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &u32) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &f32) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &i32) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &u8) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &u64) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &f64) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &i8) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &i64) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &u16) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &usize) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &bool) -> bool

impl PartialEq for Value

fn eq(self: &Self, other: &Value) -> bool

impl PartialEq for super::Value

fn eq(self: &Self, other: &String) -> bool

impl PartialEq for super::Value

fn eq(self: &Self, other: &&str) -> bool

impl PartialEq for super::Value

fn eq(self: &Self, other: &str) -> bool

impl RefUnwindSafe for Value

impl Send for Value

impl Serialize for crate::value::Value

fn serialize<S>(self: &Self, serializer: S) -> result::Result<<S as >::Ok, <S as >::Error>
where
    S: ::serde::Serializer

impl StructuralPartialEq for Value

impl Sync for Value

impl Unpin for Value

impl UnwindSafe for Value

impl<'a> From for super::Value

fn from(f: Cow<'a, str>) -> Self

Convert copy-on-write string to Value::String.

Examples

use serde_json::Value;
use std::borrow::Cow;

let s: Cow<str> = Cow::Borrowed("lorem");
let x: Value = s.into();
use serde_json::Value;
use std::borrow::Cow;

let s: Cow<str> = Cow::Owned("lorem".to_owned());
let x: Value = s.into();

impl<'de> Deserialize for crate::value::Value

fn deserialize<D>(deserializer: D) -> Result<Value, <D as >::Error>
where
    D: serde::Deserializer<'de>

impl<'de> Deserializer for crate::value::Value

fn deserialize_any<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_i8<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_i16<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_i32<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_i64<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_i128<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_u8<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_u16<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_u32<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_u64<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_u128<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_f32<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_f64<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_option<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_enum<V>(self: Self, name: &'static str, variants: &'static [&'static str], visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_newtype_struct<V>(self: Self, name: &'static str, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_bool<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_char<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_str<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_string<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_bytes<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_byte_buf<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_unit<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_unit_struct<V>(self: Self, _name: &'static str, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_seq<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_tuple<V>(self: Self, _len: usize, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_tuple_struct<V>(self: Self, _name: &'static str, _len: usize, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_map<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_struct<V>(self: Self, _name: &'static str, _fields: &'static [&'static str], visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_identifier<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>
fn deserialize_ignored_any<V>(self: Self, visitor: V) -> Result<<V as >::Value, Error>
where
    V: Visitor<'de>

impl<'de> IntoDeserializer for crate::value::Value

fn into_deserializer(self: Self) -> <Self as >::Deserializer

impl<I> Index for super::Value

fn index(self: &Self, index: I) -> &Value

Index into a serde_json::Value using the syntax value[0] or value["k"].

Returns Value::Null if the type of self does not match the type of the index, for example if the index is a string and self is an array or a number. Also returns Value::Null if the given key does not exist in the map or the given index is not within the bounds of the array.

For retrieving deeply nested values, you should have a look at the Value::pointer method.

Examples

# use serde_json::json;
#
let data = json!({
    "x": {
        "y": ["z", "zz"]
    }
});

assert_eq!(data["x"]["y"], json!(["z", "zz"]));
assert_eq!(data["x"]["y"][0], json!("z"));

assert_eq!(data["a"], json!(null)); // returns null for undefined values
assert_eq!(data["a"]["b"], json!(null)); // does not panic

impl<I> IndexMut for super::Value

fn index_mut(self: &mut Self, index: I) -> &mut Value

Write into a serde_json::Value using the syntax value[0] = ... or value["k"] = ....

If the index is a number, the value must be an array of length bigger than the index. Indexing into a value that is not an array or an array that is too small will panic.

If the index is a string, the value must be an object or null which is treated like an empty object. If the key is not already present in the object, it will be inserted with a value of null. Indexing into a value that is neither an object nor null will panic.

Examples

# use serde_json::json;
#
let mut data = json!({ "x": 0 });

// replace an existing key
data["x"] = json!(1);

// insert a new key
data["y"] = json!([false, false, false]);

// replace an array value
data["y"][0] = json!(true);

// inserted a deeply nested key
data["a"]["b"]["c"]["d"] = json!(true);

println!("{}", data);

impl<K: Into<alloc::string::String>, V: Into<super::Value>> FromIterator for super::Value

fn from_iter<I: IntoIterator<Item = (K, V)>>(iter: I) -> Self

Create a Value::Object by collecting an iterator of key-value pairs.

Examples

use serde_json::Value;

let v: Vec<_> = vec![("lorem", 40), ("ipsum", 2)];
let x: Value = v.into_iter().collect();

impl<T> Any for Value

fn type_id(self: &Self) -> TypeId

impl<T> Borrow for Value

fn borrow(self: &Self) -> &T

impl<T> BorrowMut for Value

fn borrow_mut(self: &mut Self) -> &mut T

impl<T> CloneToUninit for Value

unsafe fn clone_to_uninit(self: &Self, dest: *mut u8)

impl<T> DeserializeOwned for Value

impl<T> From for Value

fn from(t: T) -> T

Returns the argument unchanged.

impl<T> From for super::Value

fn from(opt: Option<T>) -> Self

impl<T> ToOwned for Value

fn to_owned(self: &Self) -> T
fn clone_into(self: &Self, target: &mut T)

impl<T> ToString for Value

fn to_string(self: &Self) -> String

impl<T, U> Into for Value

fn into(self: Self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

impl<T, U> TryFrom for Value

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

impl<T, U> TryInto for Value

fn try_into(self: Self) -> Result<U, <U as TryFrom<T>>::Error>

impl<T: Clone + Into<super::Value>> From for super::Value

fn from(f: &[T]) -> Self

Convert a slice to Value::Array.

Examples

use serde_json::Value;

let v: &[&str] = &["lorem", "ipsum", "dolor"];
let x: Value = v.into();

impl<T: Into<super::Value>> From for super::Value

fn from(f: Vec<T>) -> Self

Convert a Vec to Value::Array.

Examples

use serde_json::Value;

let v = vec!["lorem", "ipsum", "dolor"];
let x: Value = v.into();

impl<T: Into<super::Value>> FromIterator for super::Value

fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self

Create a Value::Array by collecting an iterator of array elements.

Examples

use serde_json::Value;

let v = std::iter::repeat(42).take(5);
let x: Value = v.collect();
use serde_json::Value;

let v: Vec<_> = vec!["lorem", "ipsum", "dolor"];
let x: Value = v.into_iter().collect();
use std::iter::FromIterator;
use serde_json::Value;

let x: Value = Value::from_iter(vec!["lorem", "ipsum", "dolor"]);

impl<T: Into<super::Value>, N: usize> From for super::Value

fn from(array: [T; N]) -> Self