How to check whether an array is subset of another array using JavaScript ?
Last Updated :
13 Jul, 2023
Improve
The task is to check whether an array is a subset of another array with the help of JavaScript. There are a few approaches, we will discuss below:
Approaches:
Approach 1: Using JavaScript array.every() method
This approach checks whether every element of the second array is present in the first array or not.
Example: This example uses the approach discussed above.
// Creating 2 arrays
let arr1 = ["GFG", "Geeks", "Portal",
"Geek", "GFG_1", "GFG_2"];
let arr2 = ["GFG", "Geeks", "Geek"];
// Funtion to check subarray
function GFG_Fun() {
let res = arr2.every(function (val) {
return arr1.indexOf(val) >= 0;
});
let not = "";
if (!res) {
not = "not";
}
// Display the output
console.log("Array_2 is " + not
+ " the subset of Array_1");
}
GFG_Fun();
Output
Array_2 is the subset of Array_1
Approach 2: Using JavaScript array.some() method
This approach declares false if some element of the second array is not present in the first array.
Example: This example uses the approach discussed above.
// Create input arrays
let arr1 = ["GFG", "Geeks", "Portal",
"Geek", "GFG_1", "GFG_2"];
let arr2 = ["GFG", "Geeks", "GeekForGeeks"];
// Function to check subarrays
function GFG_Fun() {
let res = !arr2.some(val => arr1.indexOf(val) === -1);
let not = "";
if (!res) {
not = "not";
}
// Display output
console.log("Array_2 is " + not
+ " the subset of Array_1");
}
GFG_Fun();
Output
Array_2 is not the subset of Array_1
