How to useObject.is() in Javascript
Object.is() determines whether two values are the same value. Two values are the same if both are undefined, both null, both true or both false, both strings of the same length with the same characters in the same order, both the same object (meaning both values reference the same object in memory), both numbers and both +0, both -0, both NaN, or both non-zero and both not NaN and both have the same value
Key Difference Between Object.is() and === (Strict Equality)
- Object.is(+0,0) is false, Object.is(NaN,NaN) is true.
- So Object.is() is just === with different behavior for negative zero -0 and NaN.
Syntax :
Object.is(value1, value2);
Example : In this example, the Object.is() method is checking if the provided value is of the specified type.
Javascript
// Evaluation result is the same as using ===console.log(Object.is(25, 25)); // trueconsole.log(Object.is('foo', 'foo')); // trueconsole.log(Object.is('foo', 'bar')); // falseconsole.log(Object.is(null, null)); // trueconsole.log(Object.is(undefined, undefined)); // trueconsole.log(Object.is([], [])); // falselet foo = { a: 1 };let bar = { a: 1 };console.log(Object.is(foo, foo)); // trueconsole.log(Object.is(foo, bar)); // false |
true true false true true false true false
How to check if the provided value is of the specified type in JavaScript ?
To check if the provided value is of the specified type in JavaScript, we have multiple approaches.
Below are the approaches used to check if the provided value is of the specified type in JavaScript:
Table of Content
- Using Object.is()
- Using TypeOf Operator