how to find last value of array using javascript?

Question

I have an array in javascript. I have to find last value of that array. My code is like

var array= fruits;

and I have to find last fruit in that array.

Answer 1

Since in JavaScript arrays of size n are indexed from [0..n-1] , you can get the last element by simply indexing the array at n-1 , where is the length of the array and can be obtained by the .length property:

var lastFruit = array[array.length - 1];

If you want to get the last element and also remove it from the array, you can use the .pop methid:

var lastFruit = array.pop(); // get last element of array and remove it from array

Note: As RobG stated:

length is at least one more than the highest index, but might be greater

Answer 2

First find number of elements in array and store it on variable like

var total = array.length;

Now you can find last value of array using below code

var last = array[total-1];

Answer 3

You accomplish this by using the length of the array (fruits.length) and subtracting 1 (because the array is 0 indexed). For instance...

fruits[0]="pear";
fruits[1]="apple";
fruits[2]="peach";

So fruits.length would be 3, so fruits.length - 1 = 2. So to get the last element...

var lastFruit = fruits[fruits.length-1];

Answer 4

I have to find last value of that array

The length property is at least one higher than the highest index, however it might be higher in which case the n-1 member may not exist. Eg

// Create an array with length 10
var a = new Array(10);

// Add one member at index 0
a[0] = 'foo';

So the "last" value of the array is at index 0 and has a value of "foo". So you can start with length - 1 and search backwards for members that actually exist:

function lastValue(arr) {
  var i = arr.length;
  while (i--) {
    if (i in arr) {
      return arr[i];
    }
  }
  // If get to here, arr has no members
  return -1;
}

// All the following arrays have length 4 but different number of members
console.log(lastValue([ , , , ,]));  // -1, i.e. there are no members
console.log(lastValue([0,1, , ,]));  //  1
console.log(lastValue([0,1,2,3 ]));  //  3
console.log(lastValue([ , , ,3 ]));  //  3

If you know the Array only has numeric members (ie there are no non-numeric properties and no negative properties) you can do:

var arr = [,,'foo',,'bar',,]; // length 6, highest member is at index 4

console.log(arr[Math.max.apply(Math, Object.keys(arr))]); // 'bar'

Requires ES5 Object.keys .

Answer 5

好吧，您可以找到它的长度，然后知道最后一个索引，并可以从中获取项目

var last_item = array[array.length - 1];

Answer 6

它就像：

fruits[fruits.length-1]

Answer 7

Multiple ways to find last value of an array in javascript

• Without affecting original array

• Modifies original array

• By creating own helper method

 var arr = [1,2,3,4,5]; console.log(arr.slice(-1)[0]) console.log(arr[arr.length-1]) const [last] = [...arr].reverse(); console.log(last) console.log(arr.reverse()[0]) console.log('----------Modifies original array----------'); var arr2 = [5, 10, 15]; console.log(arr2.pop()) arr2.push(15) console.log(...arr2.splice(-1)); console.log('----------By creating own helper method------'); let arr3 = [2, 4, 6, 8, 10]; Object.defineProperty(arr3, 'last', { get: function(){ return this[this.length-1]; } }) console.log(arr3.last);