JSON
Objects
Example
{
"name":"John", "age":30, "car":null }
JSON objects
are surrounded by curly braces {}.
JSON objects
is written in key/value pairs.
Keys must be
strings, and values must be a valid JSON data type (string, number, object,
array, boolean or null).
Keys and
values are separated by a colon.
Each
key/value pair is separated by a comma.
Accessing
Object Values
You can
access the object values by using dot (.) notation:
Example
myObj
= { "name":"John", "age":30, "car":null
};
x
= myObj.name;
»
You can also
access the object values by using bracket ([]) notation:
Example
myObj
= { "name":"John", "age":30, "car":null
};
x
= myObj["name"];
»
Looping an
Object
You can loop
through object properties by using the for-in loop:
Example
myObj
= { "name":"John", "age":30, "car":null
};
for
(x in myObj) {
document.getElementById("demo").innerHTML += x;
}
»
In a for-in
loop, use the bracket notation to access the property values:
Example
myObj
= { "name":"John", "age":30, "car":null
};
for
(x in myObj) {
document.getElementById("demo").innerHTML += myObj[x];
}
»
Nested JSON
Objects
Values in a
JSON object can be another JSON object.
Example
myObj
= {
"name":"John",
"age":30,
"cars": {
"car1":"Ford",
"car2":"BMW",
"car3":"Fiat"
}
}
You can
access nested JSON objects by using the dot notation or bracket notation:
Example
x
= myObj.cars.car2;
//or:
x
= myObj.cars["car2"];
»
Modify
Values
You can use
the dot notation to modify any value in a JSON object:
Example
myObj.cars.car2
= "Mercedes";
»
You can also
use the bracket notation to modify a value in a JSON object:
Example
myObj.cars["car2"]
= "Mercedes";
»
Delete
Object Properties
Use the
delete keyword to delete properties from a JSON object:
Example
delete
myObj.cars.car2;
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