javascript add item by index code example
Example 1: javascript add item by index
// Be careful!
const arr = [ 1, 2, 3, 4 ];
arr[5] = 'Hello, world!';
console.log(arr); // [ 1, 2, 3, 4, <1 empty item>, 'Hello, world!' ]
console.log(arr.length); // 6
Example 2: javascript array push element at index
var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";
console.log(arr.join()); // Jani,Hege,Stale,Kai Jim,Borge
arr.splice(2, 0, "Lene");
console.log(arr.join()); // Jani,Hege,Lene,Stale,Kai Jim,Borge
Example 3: javascript add array to array at index
a1.splice(2, 0, ...a2);
Example 4: add new element by index js
const arr = [ 1, 2, 3, 4 ];
arr[5] = 'Hello, world!';
console.log(arr); // [ 1, 2, 3, 4, <1 empty item>, 'Hello, world!' ]
console.log(arr.length); // 6