How to Insert Element into Arrays At Specific Position

const num = 1234;
const arr = num.toString().split('')
arr.splice(2, 0, ':');
const str = arr.join('');
console.log(str)

Inserting element in an array with position

This code should work.

#include <stdio.h>
#include <stdlib.h>

int main(void) {
    int *array;

    int size = 0;

    int position, value;

    printf("How many elements do you want to add? ");
    scanf("%d", &size);

    printf("\nEnter the values: \n");

    // allocate the array
    array = malloc(size * sizeof(int));

    // insert the elements
    for(int i = 0; i < size; i++) {
      scanf("%d", &array[i]);
    }

    // print the array
    for(int i = 0; i < size; i++) {
      printf("%d ", array[i]);
    }
    printf("\n");

    // read the position
    printf("In which position you want to enter the element? ");
    scanf("%d",&position);

    // resize the array
    size++;
    array = realloc(array, size * sizeof(int));

    // set the position to the true value
    position--;

    // read the value
    printf("Which element do you want to insert? ");
    scanf("%d", &value);

    // move the elements
    for(int i = size - 1; i > position; i--) {
      array[i] = array[i - 1];
    }

    // insert the array
    array[position] = value;

    // print the value
    for(int i = 0; i < size; i++) {
      printf("%d ", array[i]);
    }
    printf("\n");
}

Of course you should implement some error handling. Especially for the alloc.

Insert new item in array on any position in PHP

You may find this a little more intuitive. It only requires one function call to array_splice:

$original = array( 'a', 'b', 'c', 'd', 'e' );
$inserted = array( 'x' ); // not necessarily an array, see manual quote
 
array_splice( $original, 3, 0, $inserted ); // splice in at position 3
// $original is now a b c x d e

If replacement is just one element it is not necessary to put array() around it, unless the element is an array itself, an object or NULL.

RETURN VALUE: To be noted that the function does not return the desired substitution. The $original is passed by reference and edited in place. See the expression array &$array with & in the parameters list .

How to insert item at certain positions in a multiple array loop

Perhaps I misunderstood something. I assumed the following:

:: The lengths of each array in the data array are the same.

:: You need to inject after each position, which will mess up a for loop that increase it's i(teration) variable.

:: There is always a Path and a Score in the first array.

:: You want to add a new value after each value, apart from the two above.

Solution

1. Get the length of each array: data[0].length
2. Loop from the end.
3. Ignore last position.
4. Ignore the first position
5. Splice different value based on if it's the first item in the data array.

I loop over each value once, but I do it in the order of: 'Item5', 4, 6, 3, 3, 'Item4', 2, 5, 5, 2, 'Item3', ...

const data = [
  ['Path', 'Item1', 'Item2', 'Item3', 'Item4', 'Item5', 'Score'],
  ['/path-one', 1, 3, 2, 2, 4,  3],
  ['/path-two', 4, 5, 5, 5, 6, 3],
  ['/path-three', 5, 5, 3, 5, 3, 3],
  ['/path-four', 2, 3, 4, 2, 2, 3],
]

function mapArray(data) {
  let secondToLastItem = data[0].length - 2; // 1 & 3
  let FIRST_ITEM = 0; // 4

  for (let index = secondToLastItem; index > FIRST_ITEM; index--) { // 2
    for (let item = 0; item < data.length; item++) {
      let injectedValue = (item == FIRST_ITEM)  // 5
          ? {'role': 'annotation'}
          : data[item][index]; 
      
      data[item].splice(index + 1, 0, injectedValue);
    }
  }
  
  return data;
}

console.log( mapArray(data) );

import numpy as np

# need to take the indices based on the array before anything is inserted
J = [[4, 6, 8]]
C1 = [0]

A = [np.array([10.                 ,  0.6382821834929432 ,  0.5928417218382795 ,
        0.5542698411479658 ,  0.6677634679746701 ,  0.8578897621707481 ,
        0.6544597670890333 ,  0.32706383813570833,  0.8966468940380192 ])]

A = np.insert(A[0], J[0], C1[0])

array([10.        ,  0.63828218,  0.59284172,  0.55426984,  0.        ,
        0.66776347,  0.85788976,  0.        ,  0.65445977,  0.32706384,
        0.        ,  0.89664689])

J = [[4, 7, 10]]
C1 = [0]

A = [np.array([10.                 ,  0.6382821834929432 ,  0.5928417218382795 ,
        0.5542698411479658 ,  0.6677634679746701 ,  0.8578897621707481 ,
        0.6544597670890333 ,  0.32706383813570833,  0.8966468940380192 ])]

for elem in J[0]:
    A = [np.insert(A[0], elem, C1[0])]