What is the Difference between == and === in JavaScript?

 In JavaScript, there are two comparison operators used to check equality: == and ===. While both operators are used for comparison, there is a difference between them.

The == operator checks for equality of values, but performs type coercion if the operands have different types. In other words, it converts the operands to a common type before comparing. For example, 1 == '1' is true, since the string '1' is converted to the number 1 before comparison.

On the other hand, the === operator checks for equality of values and type. It only returns true if the operands are of the same type and have the same value. For example, 1 === '1' is false, since the operands have different types.

Here are some examples that illustrate the difference between == and ===:

javascript
console.log(1 == '1'); // true
console.log(1 === '1'); // false

console.log(null == undefined); // true
console.log(null === undefined); // false

console.log(false == 0); // true
console.log(false === 0); // false

console.log(true == 1); // true
console.log(true === 1); // false

In the first example, 1 == '1' returns true because the == operator performs type coercion and converts the string '1' to the number 1 before comparison. However, 1 === '1' returns false because the === operator does not perform type coercion and the operands have different types.

In the second example, null == undefined returns true because both null and undefined are considered equal values by the == operator. However, null === undefined returns false because the operands have different types.

In the third example, false == 0 returns true because the == operator converts false to 0 before comparison. However, false === 0 returns false because the operands have different types.

In the fourth example, true == 1 returns true because the == operator converts true to 1 before comparison. However, true === 1 returns false because the operands have different types.