Removing elements from JavaScript arrays

Question

I have the following array setup, i,e:

var myArray = new Array();

Using this array, I am creating a breadcrumb menu dynamically as the user add

Answer 1

I like this implementation of Array.remove, it basically abstracts the use of the splice function:

// Array Remove - By John Resig (MIT Licensed)
Array.prototype.remove = function(from, to) {
  var rest = this.slice((to || from) + 1 || this.length);
  this.length = from < 0 ? this.length + from : from;
  return this.push.apply(this, rest);
};

Usage:

// Remove the second item from the array
array.remove(1);
// Remove the second-to-last item from the array
array.remove(-2);
// Remove the second and third items from the array
array.remove(1,2);
// Remove the last and second-to-last items from the array
array.remove(-2,-1);

Answer 2

You do not need to write a function, you can use indexOf() and splice() these two functions.

You can remove any positional element a element. For example: var name = ['james' , 'tommy' , 'Jimmy' , 'Holon']; var name = name.splice(name.indexOf('Jimmy') , 1);

Answer 3

You could use myArray.push('MenuA'); so you don't specify direct numbers when adding elements.

To remove an element I.E. 'MenuB':

// another quick way to define an array
myArray = ['MenuA', 'MenuB', 'MenuC', 'MenuD', 'MenuE']; 

// remove an item by value:
myArray.splice(myArray.indexOf('MenuB'),1);

// push a new one on
myArray.push('MenuZ');

// myArray === ["MenuA", "MenuC", "MenuD", "MenuE", "MenuZ"]

Answer 4

http://www.w3schools.com/jsref/jsref_splice.asp

Splice should recalculate the correct indexes for future access.

Answer 5

Remove array element by position/element(Actual array modifies)

1 - arr.splice(1, 1) -----> (index, no of elements)

2 - arr.splice(arr.indexOf(5), 1) -----> (array.indexOf(InputValue), no of elements)

let arr = [1,2,3,4,5];
console.log(arr.splice(1,1));                // [2]
console.log(arr.splice(arr.indexOf(5), 1));  // [5]
console.log(arr);                            // [1, 3, 4]

Remove array element by position/element(creates copy array)

let arr2 = [10, 20, 30, 40]
let result = arr2.filter(a=> a!==20);
let result2 = arr2.filter(a=> a!==arr2[arr2.indexOf(30)])
console.log(result)    // [10, 30, 40]
console.log(result2)   // [10, 20, 40]