12 Beginner Mistakes and Errors in JavaScript You Should Know

 12 Beginner Mistakes and Errors in JavaScript You Should Know

Friends, we all know JavaScript is a very popular programming language for developing the website and the web app.

However, learning JavaScript as a beginner can be difficult, friends. We will have find some of the most common problems beginners face in JavaScript and how to solve them.

1. Understanding Variables and Data Types

Friends, one of the first things when you learn the JavaScript variables. Variables are used to store information. The beginner coder many times confused in different data types such as number, string and Boolean.

For example, if you try to add a number and a string, you may get an unexpected result:

I will take this following example

let result = 1 + "1";

Output of this program is 11 not 2

Tip: Friends, always make sure you know the type of data you are working with. You can use the typeof keyword to check.

2. Forgetting to Declare Variables

Friends, in JavaScript we use let, const and var keywords for declaring the variable, but without that also in JavaScript we can declare the variable, but cause later many logical issues.

x = 10; // this variable is not declared properly

Friends, this bugs hard to find. It is always better to declare variables properly.

Tip: Use let or const to declare all your variables. Avoid using friends var unless you understand how it works.

3. Using Assignment Instead of Comparison

Friends, another common mistake is using the assignment operator = instead of the comparison operator == or ===.

if (x = 5) {

//

}

This will always run because x is assigned, not compared.

Friends, this mistakes are very difficult to find because it does not cause an error, but the code will not work as expected.

Tip: Friends, you can use === for comparison for not occur logical errors.

4. Not Understanding Scope

Friends, scope refers to where variables are available in your code. Friends, at beginning time we lot confuse about variable is accessible or not in certain scope.

Friends, always remember a variable declared inside a function is not available outside that function:

function greet() {

let message = "Hello";

}

console.log(message);

Friend, error is occurred because it is declare in function.

Tip: Friends, learn the difference between local and global variables. Use functions carefully and avoid declaring global variables unless necessary.

5. Problems with Asynchronous Code

In JavaScript, some tasks take time, like loading data from a server. These tasks don’t happen instantly, but beginners many times expect them to finish right away.

For example:

let data = fetchData(); // This may not return the data immediately

console.log(data); // Might show undefined

Tip: Friends, learn how to use promises and async/await to handle asynchronous code properly.

6. Confusing null, undefined, and NaN

Friends, this three keywords there meaning look same but they are different.

1. null is a value that means "no value."

2. undefined means the variable has been declared but not given a value.

3. NaN full form is "Not a Number" for check it is number or not.

Tip: You use console.log() for output, use that.

7. Not Using the Console for Debugging

Check and analyse our code step by step because once you understand how code is working then you understand many things.

Tip: Friends, use console.log and analyse what our code is doing.

8. Writing Too Much Code Without Testing

Friends, don't write lot of code directly. Write code properly by thinking whether it is correct or not because this make very difficult to find errors.

Tip: Test your code often. Make small changes and check if they work before moving on.

9. Copying Code Without Understanding

Friends, don't copy and paste code. Understand the code, friends, what is code doing because it enhance lot of your coding skills.

Tip: Always take time to understand what the code does before using it.

10. Giving Up Too Soon

Friends, don't give up early because in starting project are not build by us and lot of errors occur, but don't stress. Try understand, do small portion of code daily.

Tip: Keep practicing. Every developer makes mistakes. The important thing is to learn from them.

11. Not Learning from Errors

Friends, you should understand why this error come. Take care of not repeating same mistakes, friends, it is also important.

12. Understand Syntax Properly

Because as a beginner we don't understand syntax properly, because of that lot of errors occurs.

Read more:How long does it take to learn JavaScript

This 12 common problem that occurs JavaScript learner as a beginner. If you know this mistake, then you definitely become better developer.

Frequently asked questions 

1.What are the basic code errors?

Ans.Syntax error runtime error and logical errors are the basic code errors 

2.What is the full form of OOP?

Ans:OOP Full form is object oriented programming.