push a value in array on particular index javascript code example

Example 1: javascript push in specific index

arr.splice(index, 0, item);
//explanation:
inserts "item" at the specified "index",
deleting 0 other items before it

Example 2: add an object to index 0 array js

//Add an object to start of array
splice(index,noOfItemstoDelete,item);
ex - arr.splice(0,0,item);