Use JavaScript equality operator === (and, actually, ==) to test reference equality (e.g., that they refer to the same object/ array/ function).
Check if two vars have the same reference
foo == bar
foo === barJavaScript reference equality
Simple example code reference types like objects, == or === operators check its reference only. e.g
<!DOCTYPE html>
<html>
<body>
<script>
let a= { text:'my text', val:'my val'}
let b= { text:'my text', val:'my val'}
console.log("a == b", a==b)
b = a;
console.log("Reference of both variable are same", a==b)
</script>
</body>
</html>
Output:
let a= { text:'my text', val:'my val'}
let b= { text:'my text', val:'my val'}Here a==b will be false as a reference of both variables are different though their content is the same. But if I change it to
a=band if I check now a==b then it will be true, since references of both variables are the same now.
More examples
<script>
var a = 1;
var b = 1;
console.log(a == b); // true
var c = 10;
var d = "10";
console.log(c == d); // true
const name1 = {
first_name: "sarah",
};
const name2 = {
first_name: "sarah",
};
console.log(name1 == name2); // false
</script><script>
var a = 1;
var b = 1;
console.log(a === b); // true
var c = 10;
var d = "10";
console.log(c === d); // false
const name1 = {
first_name: "sarah",
};
const name2 = {
first_name: "sarah",
};
console.log(name1 === name2); // false
</script>Do comment if you have any doubts or suggestions on this JS equality topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version