Check out example codes for "typescript splice". It will help you in understanding the concepts better.

Code Example 1

const months = ['Jan', 'March', 'April', 'June'];
months.splice(1, 0, 'Feb');
// inserts at index 1
console.log(months);
// expected output: Array ["Jan", "Feb", "March", "April", "June"]

months.splice(4, 1, 'May');
// replaces 1 element at index 4
console.log(months);
// expected output: Array ["Jan", "Feb", "March", "April", "May"]

months.splice(0, 1);
// removes 1 element at index 0
console.log(months);
// expected output: Array ["Feb", "March", "April", "May"]

Code Example 2

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);

Code Example 3

var arr = ["orange", "mango", "banana", "sugar", "tea"];  
var removed = arr.splice(2, 0, "water");  
console.log(arr);  // orange,mango,water,banana,sugar,tea 
console.log(removed); // banana

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