Why My First JavaScript Button Didn’t Work -Explain in detail

 My First JavaScript Button Didn’t Work – This Is What I Did Wrong

Friends, today I will tell you about the common syntax errors i make that cause our JavaScript buttons to not work. It can be very irritating when we can't find the errors quickly. Friends I’ll share my experience working on a calculator project and a toggle button project, I Will explain the most common mistakes, and provide solutions. So, let’s get started step by step!

 1: addeventlistner ('click') :

 addeventlistner('click', function() {

  //Wrong syntax 

});

Error reason:Misspelled name of function (addeventlistner) and all lowercase. JavaScript is case-sensitive, so this won’t work at all.

element.addEventListener('click', function() {

  //Right syntax 

});

2.Accessing Elements by Wrong ID or Class.

Example mistake:

Document.GetElementById('myButton')

Error reason: Document should be lowercase, and GetElementById should be getElementById

Correct :

document.body.style.backgroundColor = "black";

3 My First JavaScript Button Didn’t Work – This Is What I Did Wrong document.body.style.backgroundcolor = "black";

Error reason:The correct property is backgroundColor, not backgroundcolor

Correct:

document.body.style.backgroundColor = "black";

4.Using querySelectorAll Wrongly.

document.querySelectorAll('.myButton')

querySelectorAll returns a NodeList — not a single element. You can’t directly addeventlisteners without selecting an index.

Correct code:

document.querySelector('.myButton')

Error reason: queryselctorAll returns a NodeList, not a single element.

Complete code:

const buttons = document.querySelectorAll('.myButton');

buttons.forEach(function(btn) {

  btn.addEventListener('click', function() {

    // code

  });

});

Final code I written for toggle button:

<button id="darkToggle">Dark Mode</button>

document.body.style.backgroundColor

Javascript:

const btn = document.getElementById('darkToggle');

btn.addEventListener('click', function() {

  document.body.style.backgroundColor = "black";

});

What I Learned

• Small typos can break your code — always check spelling and case.
• Friends you Can use console.log() to Check if your element is being selected.
• If error occurs don't not worry because errors come to every programmer.
• Break your code into steps, and check each one with alerts or logs.

FAQs

1.What is the common mistake with addEventListener?

The mistake is misspelling  as addEventListener or using incorrect casing. JavaScript is case-sensitive, so this causes the code to fail.

2.Why doesn't getElementById work sometimes?

It Also fails due to incorrect capitalization, like writing Document.GetElementById instead of Document.GetElementById. JavaScript requires exact casing.