How Do I Convert a String to an Int in Javascript?

Here are some ways to convert a String to an Int in javascript:

1. parseInt() function:

var str = "123";
var num = parseInt(str);

2. Number constructor:

var str = "123";
var num = Number(str);

3. + (Unary Plus) Operator:

var str = "123";
var num = +str;

4. Bitwise OR | Operator:

var str = "123";
var num = str | 0;

Note: In above examples, if given input can not be converted to number then first three methods will return NaN and 4th will return 0.