set new key in object javascript code example

Example 1: how to add field to object in js

// original object { key1: "a", key2: "b"}
var obj = {
    key1: "a",
    key2: "b"
};

// adding new filed - you can use 2 ways
obj.key3 = "c"; // static
// or
obj["key3"] = "c"; // dynamic - 'key3' can be a variable
console.log(obj) // {key1: "a", key2: "b", key3: "c" }

Example 2: javascript add to object

var element = {}, cart = [];
element.id = id;
element.quantity = quantity;
cart.push(element);

// Array of Objects in form {element: {id: 10, quantity: 10} }
var element = {}, cart = [];
element.id = id;
element.quantity = quantity;
cart.push({element: element});

Example 3: javascript object string property

// Also useful for dynamic strings, e.g. `thing-${variable}`
myObject['thing'] = true;

Example 4: js change key value in object

var object = { boo:true, baa:5 };
console.log(object);
function change() {
  object.boo = false;
  object.baa++;
};
change();
console.log(object);
//Hope this helps!