JavaScript Comma Operator

JavaScript Comma Operator mainly evaluates its operands from left to right sequentially and returns the value of the rightmost operand.

let x = (1, 2, 3);
console.log(x);

Output:

Here is another example to show that all expressions are actually executed.

let a = 1, b = 2, c = 3;
 
let res = (a++, b++, c++);
 
console.log(res);
console.log(a, b, c);

Output:

3
2 3 4

Here is an example with function calls.

function Func1() {
    console.log('one');
    return 'one';
}
function Func2() {
    console.log('two');
    return 'two';
}
function Func3() {
    console.log('three');
    return 'three';
}
 
// Three expressions are given at one place
let x = (Func1(), Func2(), Func3());
 
console.log(x);

Output:

one
two
three
three

Javascript Assignment Operators Javascript Unary Operators