Approach 1 : Using For Loop in JavaScript

Approach 2: Using find() Method

In this approach, we are using a nested for loop, iterate through each element in an array. Compare it with every other element to find the first non-repeated element. If found, print it; otherwise, indicate that all elements are repeated.

Syntax:

for (let i in obj1) {
    // Prints all the keys in
    // obj1 on the console
    console.log(i);
}

Example: Below is the implementation of the above approach using nesting For loop.

Javascript

let arr = [9, 4, 9, 6, 7, 4];
let n = arr.length;
let nonRepeatedFound = false;

for (let i = 0; i < n; i++) {
    let j;
    for (j = 0; j < n; j++) {
        if (i != j && arr[i] == arr[j]) {
            break;
        }
    }
    if (j == n) {
        console.log(
            "The first non-repeated element is:",
            arr[i]
        );
        nonRepeatedFound = true;
        break;
    }
}
if (!nonRepeatedFound) {
    console.log(
        "All elements in the array are repeated."
    );
}

Output

The first non-repeated element is: 6

JavaScript Program to Find the First Non-Repeated Element in an Array

Finding the first non-repeated element in an array refers to identifying the initial occurrence of an element that does not occur again elsewhere within the array, indicating uniqueness among the elements.

Examples:

Input: {-1, 2, -1, 3, 0}
Output: 2
Explanation: The first number that does not repeat is : 2
Input: {9, 4, 9, 6, 7, 4}
Output: 6
Explanation: The first number that does not repeat is : 6

We have common approaches to perform this:

Table of Content

Using For Loop in JavaScript
Using find() Method
Using map() Method
Using Array Filter Method:

Tags:

#Geeks Premier League 2023 #javascript-array #JavaScript-Program #Geeks Premier League #JavaScript #Web Technologies

Approach 2: Using find() Method

Approach 1 : Using For Loop in JavaScript

JavaScript Program to Find the First Non-Repeated Element in an Array

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