How to replace and array item when there is a match with other array item code example

Example 1: remove from array javascript

let numbers = [1,2,3,4]

// to remove last element
let last_num = numbers.pop();
// numbers will now be [1,2,3]

// to remove first element
let first_num = numbers.shift();
//numbers will now be [2,3]

// to remove at an index
let number_index = 1
let index_num = numbers.splice(number_index,1); //removes 1 element at index 1
//numbers will now be [2]

//these methods will modify the numbers array and return the removed element

Example 2: splice typescript array

var arr = ["orange", "mango", "banana", "sugar", "tea"];  
var removed = arr.splice(2, 0, "water");  
console.log("After adding 1: " + arr );  
console.log("removed is: " + removed); 
          
removed = arr.splice(3, 1);  
console.log("After removing 1: " + arr );  
console.log("removed is: " + removed);