splice javascript delete code example

Example 1: replace array element javascript

// Replace 1 array element at index with item 
arr.splice(index,1,item);

Example 2: add element to array using splice

//we can add elements to array using splice

const strings=['a','b','c','d']

//go the 2nd index,remove 0 elements and then add 'alien' to it
strings.splice(2,0,'alien')

console.log(strings) //["a", "b", "alien", "c", "d"]

//what is the time complexity ???
//worst case is O(n). if we are adding to end of array then O(1)
//in our example we added to the middle of array so O(n/2)=>O(n)

Example 3: remove one element using splice

fruits = ['Banana', 'Orange', 'Apple', 'Mango'];

removeFruitByIndex(index: number) {
  this.fruits = [
    ...this.fruits.slice(0, i),
    ...this.fruits.slice(i + 1, this.fruits.length),
  ];
}


removeFruitByValue(fruite: string) {
  const i = this.descriptionsList.indexOf(fruite);
  this.fruits = [
    ...this.fruits.slice(0, i),
    ...this.fruits.slice(i + 1, this.fruits.length),
  ];
}

Example 4: splice from array javascript to remove

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

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