assigning one element from two arrays in another array

Question

If I have two arrays and I want to get one element of each of them and put it in another array. I want something like this:

var array1 = [2, 3, 8];
var array2 = [4, 6, 5];
var array3 = array1[0].push(array2[0]);

so that the output would be: array3 = [2,4] . How can I do that in javascript ?

hint: I know that the push function is used to append element to array, but what I want is to append element from one array to another element from another array. Or, appending the two elements and putting it in array.

Answer 1

You could just create an array like

var array3 = [array1[0], array2[0]]

In your code there are multiple problems

• array1[0] returns a number not a array so it doesn't have the push method
• Even if you use array1.slice(0,1) to get an array with first element, the push() method will return an number(length of the array - 2) so the assignment won't work

so another way is

var array3 = array1.slice(0,1);
array3.push(array2[0])

Answer 2

I think you are looking for something like this:

var array3 = [];
    array3.push(array1[0]);
    array3.push(array2[0]);

I created an empty new array, and then added elements to it - easy as that!

You may also want to look at the array.splice function :)

Answer 3

This works with as many arrays as you want

function getArray (n) {
    var newArray = [];
    if (arguments[1][0] instanceof Array) {
        for (var i = 0; i < arguments[1].length; i += 1) {
            newArray.push(arguments[1][i][n]);
        }
    } else {
        for (var i = 1; i < arguments.length; i += 1) {
             newArray.push(arguments[i][n]);
        }
    }
    return newArray;
}

Lemme give you some examples to show you how this works:

getArray( index , array1 , array2 , so on... )

1:

> getArray(0, [1,2,3], [4,5,6])

[1,4]

2:

> getArray(1, [1,2,3], [4,5,6])

[2,5]

3:

> getArray(0, [1,2,3], [4,5,6], [7,8,9])

[1,4,7]

4:

 getArray(0, [ \n[1,2,3], \n[4,5,6] \n])  

[1,4]

Your way

According to your description, you can use this like:

var array1 = [1,2,3];
var array2 = [4,6,5];

var array3 = genArray(0, array1, array2);

Answer 4

jquery slice method is used to returns the array element which you want. for example:

   var fruits = ["Banana", "Orange", "Lemon", "Apple", "Mango"];
   var a = ["fruit","veg"];
   var newarray = fruits.slice(0,1); 
   newarray.push(a[0])
   alert(newarray)

if you want to insert/delete method form array element use splice method. the major difference between : slice method : it return new array element without modified existing array element. it needs two arguments for start & EndIndex. For eg:

var a[3,4,5]
a.slice(0,1) // it returns [3]

splice method : Deletes and/or inserts elements in an array. Unlike slice(), the splice() method modifies the original array and returns a new array. it needs three arguments and, third argument is optional.The first parameter is the index to start deleting and/or insert elements, the second param is number of elements to remove and third param (optional) is the new elements to be added to the array.For eg:

 Var a = [1,2,5,6]
    var b = [3,4]
    a.splice().apply(a,[2,0].concat(b)) // a insert new element as [1,2,3,4,5,6]

//or if you want replace and append new element below like as:

 a.splice().apply(a,[2,1].concat(b)) // a delete [5] element and return as new array as [1,2,3,4,6]