The double equal “==” is an auto-type conversion and it checks only value not type.

The three equal “===” is not auto-type conversion and it check value and type both.

The REAL example as given below:

if(1 == ”1”) // Its returns true because it's an auto-type conversion and it checks only value not type.
if(1 === ”1”) // Its returns false because it's not auto-type conversion and it check value and type both.
If(1=== parseInt(”1”)) // Its returns true.
// alert(0 == false); // RETURN true, because both are same type.
// alert(0 === false); // return false, because both are of a different type.
// alert(1 == "1"); // return true, automatic type conversion for value only.
// alert(1 === "1"); // return false, because both are of a different type.
// alert(null == undefined); // return true.
// alert(null === undefined); // return false.
//alert('0' == false); // return true.
// alert('0' === false); // return false.
// alert(1=== parseInt("1")); // return true.

The double equal “==” is an auto-type conversion and it checks only value not type.

The three equal “===” is not auto-type conversion and it check value and type both.

The real example as given below:

if(1 == ”1”) // Its returns true because it's an auto-type conversion and it checks only value not type.
if(1 === ”1”) // Its returns false because it's not auto-type conversion and it check value and type both.
If(1=== parseInt(”1”)) // Its returns true.
// alert(0 == false); // return true, because both are same type.
// alert(0 === false); // return false, because both are of a different type.
// alert(1 == "1"); // return true, automatic type conversion for value only.
// alert(1 === "1"); // return false, because both are of a different type.
// alert(null == undefined); // return true.
// alert(null === undefined); // return false.
//alert('0' == false); // return true.
// alert('0' === false); // return false.
// alert(1=== parseInt("1")); // return true.