Fill a JavaScript array with values inserted in the middle position

Question

Fill a JavaScript array with values inserted in the middle position

I'm having trouble populating an array:

var arr2 = ["x", "y", "z"];

I want to insert a random number/value between each original value using a for loop, like this:

for (let i = 1; i < arr2.length; i+2) {
   arr2.splice(i, 0, Math.random());
}

But my browser freezes because the length of arr2 changes with every splice, creating an infinite loop. I tried another approach:

var len = arr2.length;

for(let j = 1; j < len; j+2) {
   arr2.splice(j, 0, Math.random());
}

Now things are not working as expected. I suspect that len is changing again.

I need to increment j by two because after the first splice, arr2 looks like this:

["x", Math.random(), "y", "z"];

However, since j = 3 and the condition is j < len, the only explanation is that len is being modified once more.

Any insights would be appreciated. Ultimately, I want the array to end up like this:

arr2 = ["x", Math.random(), "y", Math.random(), "z"];

javascript arrays splice

Answer 1

Answer №1

for (var x = 1; x < list2.length; x+2) {

The variable x is not properly incrementing in this line. Please update it to:

for (var x = 1; x < list2.length; x+=2) {

Using += will ensure that x increases by 2 each time.

Answer 2

for (var x = 1; x < list2.length; x+2) {

The variable x is not properly incrementing in this line. Please update it to:

for (var x = 1; x < list2.length; x+=2) {

Using += will ensure that x increases by 2 each time.

Answer 3

Answer №2

Here is a suggestion you might want to consider:

let letters = ["a", "b", "c"];

let length = letters.length;

// Iterate through all elements except the last one with step of 1
for(let index = 0; index < (length - 1); ++index) {
   // Insert undefined starting from index 1 and moving 2 steps for each element
   letters.splice(1 + (index * 2), 0, undefined);
}

Answer 4

Here is a suggestion you might want to consider:

let letters = ["a", "b", "c"];

let length = letters.length;

// Iterate through all elements except the last one with step of 1
for(let index = 0; index < (length - 1); ++index) {
   // Insert undefined starting from index 1 and moving 2 steps for each element
   letters.splice(1 + (index * 2), 0, undefined);
}

Answer 5

Answer №3

Here's a simple way to achieve the desired result:

let myArray = ["x", "y", "z"],
    lengthOfArray = myArray.length,
    finalOutput = [];

for ( let j = 0; j < lengthOfArray; j++ ) {
  finalOutput.push(myArray[j]);
  if ( j < lengthOfArray - 1 ) {
    finalOutput.push(null);
  }
}

// final output:
// ["x", null, "y", null, "z"]

Answer 6

Here's a simple way to achieve the desired result:

let myArray = ["x", "y", "z"],
    lengthOfArray = myArray.length,
    finalOutput = [];

for ( let j = 0; j < lengthOfArray; j++ ) {
  finalOutput.push(myArray[j]);
  if ( j < lengthOfArray - 1 ) {
    finalOutput.push(null);
  }
}

// final output:
// ["x", null, "y", null, "z"]

Fill a JavaScript array with values inserted in the middle position

Answer №1

Answer №2

Answer №3

Similar questions

Attempting to develop a worldwide npm package. Upon running my script, I encounter the message "The designated path cannot be found."

Angular: How to Disable Checkbox

Is it possible to edit YouTube images or embed YouTube iframes without needing an account?

How can serial numbers be sorted using a JavaScript If Statement based on 2 criteria?

Variations in ajax requests coupled with a polling mechanism

Error message: The variable "data" is not defined in next.js

The ajax response is returning the entire page's html code instead of just the text content from the editor

Leveraging the jQuery live() function to optimize heavy usage of Ajax on a website

What is the best way to cause an error to occur upon launching an ExpressJS server?

Executing Javascript dynamically in VueJS: Learn how to run code from a string efficiently

Creating artwork: How to resize images without losing clarity

Adjusting the size of <nav> element to accommodate its child elements

"Learn how to add up elements in an array based on their unique IDs and generate a new array using

Creating a table with a static first column and vertical text positioned to the left of the fixed column

A tool developed in Javascript that allows for the conversion of .ini files to .json files directly on the client

How to set and update the value of a TextField in ReactJS using useState and implement an onchange event handler for the input field in TypeScript

Arrange divs on the screen in a specific formation

Encountered an issue while trying to install npm package express-generator globally

Is there a way to direct the user's cursor to a specific location on the page when they hover over an image?

Should the Express.js router be required directly or stored in a variable before use?