how to push something into an array in a specific index code example

Example 1: javascript insert item into array

var colors=["red","blue"];
var index=1;

//insert "white" at index 1
colors.splice(index, 0, "white");   //colors =  ["red", "white", "blue"]

Example 2: insert element in an array at specific position

/*
 * Program  : Inserting an element in the array
 * Language : C
 */

#include<stdio.h>

#define size 5

int main()
{
    int arr[size] = {1, 20, 5, 78, 30};
    int element, pos, i;

    printf("Enter position and element\n");
    scanf("%d%d",&pos,&element);

    if(pos <= size && pos >= 0)
    {
        //shift all the elements from the last index to pos by 1 position to right
        for(i = size; i > pos; i--)
            arr[i] = arr[i-1];

        //insert element at the given position
        arr[pos] = element;

        /*
         * print the new array
         * the new array size will be size+1(actual size+new element)
         * so, use i <= size in for loop
         */
        for(i = 0; i <= size; i++)
            printf("%d ", arr[i]);
    }
    else
        printf("Invalid Position\n");

    return 0;
  }