array.splice javascript

let arr = ['foo', 'bar', 10, 'qux'];

// arr.splice(<index>, <steps>, [elements ...]);

arr.splice(1, 1);			// Removes 1 item at index 1
// => ['foo', 10, 'qux']

arr.splice(2, 1, 'tmp');	// Replaces 1 item at index 2 with 'tmp'
// => ['foo', 10, 'tmp']

arr.splice(0, 1, 'x', 'y');	// Inserts 'x' and 'y' replacing 1 item at index 0
// => ['x', 'y', 10, 'tmp']

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"]

let myFish = ['angel', 'clown', 'drum', 'mandarin', 'sturgeon']
let removed = myFish.splice(3, 1)

// removed is ["mandarin"]
// myFish is ["angel", "clown", "drum", "sturgeon"] 

let myFish = ['angel', 'clown', 'mandarin', 'sturgeon']
//insert new element into array at index 2
let removed = myFish.splice(2, 0, 'drum')

// myFish is ["angel", "clown", "drum", "mandarin", "sturgeon"] 
// removed is [], no elements removed

let arrDeletedItems = array.splice(start[, deleteCount[, item1[, item2[, ...]]]])

let myFish = ['angel', 'clown', 'mandarin', 'sturgeon']
let removed = myFish.splice(2, 0, 'drum')

// myFish is ["angel", "clown", "drum", "mandarin", "sturgeon"] 
// removed is [], no elements removed