Thestrict equality (===) operator checks whether its two operands areequal, returning a Boolean result. Unlike theequality operator,the strict equality operator always considers operands of different types to bedifferent.

Try it

console.log(1 === 1);// Expected output: trueconsole.log("hello" === "hello");// Expected output: trueconsole.log("1" === 1);// Expected output: falseconsole.log(0 === false);// Expected output: false

Syntax

x === y

Description

The strict equality operators (=== and!==) provide theIsStrictlyEqual semantic.

• If the operands are of different types, returnfalse.
• If both operands are objects, returntrue only if they refer to thesame object.
• If both operands arenull or both operands areundefined,returntrue.
• If either operand isNaN, returnfalse.
• Otherwise, compare the two operand's values:
  • Numbers must have the same numeric values.+0 and-0are considered to be the same value.
  • Strings must have the same characters in the same order.
  • Booleans must be bothtrue or bothfalse.

The most notable difference between this operator and theequality(==) operator is that if the operands are of different types, the== operator attempts to convert them to the same type before comparing.

Examples

Comparing operands of the same type

"hello" === "hello"; // true"hello" === "hola"; // false3 === 3; // true3 === 4; // falsetrue === true; // truetrue === false; // falsenull === null; // true

Comparing operands of different types

"3" === 3; // falsetrue === 1; // falsenull === undefined; // false3 === new Number(3); // false

Comparing objects

const object1 = {  key: "value",};const object2 = {  key: "value",};console.log(object1 === object2); // falseconsole.log(object1 === object1); // true

Specifications

Browser compatibility

See also

• Equality (==)
• Inequality (!=)
• Strict inequality (!==)