JavaScript Debugging

JavaScript Debugging with javascript, innerhtml, tutorials, examples, html, dom, css, tags, events, validation, object, loop, array, document etc.

<< Back to JAVASCRIPT

next → ← prev

JavaScript Debugging

Sometimes a code may contain certain mistakes. Being a scripting language, JavaScript didn't show any error message in a browser. But these mistakes can affect the output.

The best practice to find out the error is to debug the code. The code can be debugged easily by using web browsers like Google Chrome, Mozilla Firebox.

JavaScript Debugging Example

Here, we will find out errors using built-in web browser debugger. To perform debugging, we can use any of the following approaches:

Using console.log() method
Using debugger keyword

Using console.log() method

The console.log() method displays the result in the console of the browser. If there is any mistake in the code, it generates the error message.

Let's see the simple example to print the result on console.

<script>
x = 10;
y = 15;
z = x + y;
console.log(z);
console.log(a);//a is not intialized
</script>

Output:

To open the console on browser, press F12 key.

Using debugger keyword

In debugging, generally we set breakpoints to examine each line of code step by step. There is no requirement to perform this task manually in JavaScript.

JavaScript provides debugger keyword to set the breakpoint through the code itself. The debugger stops the execution of the program at the position it is applied. Now, we can start the flow of execution manually. If an exception occurs, the execution will stop again on that particular line.

<script>
x = 10;
y = 15;
z = x + y;
debugger;
document.write(z);
document.write(a);
</script>

Output:

Next TopicJavaScript Hoisting

← prev next →

.Net

.NET Array Dictionary List String 2D Async DataTable Dates DateTime Enum File For Foreach Format IEnumerable If IndexOf Lambda LINQ Parse Path Process Property Regex Replace Sort Split Static StringBuilder Substring Switch Tuple

Java

Core Array ArrayList HashMap String 2D Cast Character Console Deque Duplicates File For Format HashSet If IndexOf Lambda Math ParseInt Process Random Regex Replace Sort Split StringBuilder Substring Switch Vector While

Related Links

Adjectives Ado Ai Android Angular Antonyms Apache Articles Asp Autocad Automata Aws Azure Basic Binary Bitcoin Blockchain C Cassandra Change Coa Computer Control Cpp Create Creating C-Sharp Cyber Daa Data Dbms Deletion Devops Difference Discrete Es6 Ethical Examples Features Firebase Flutter Fs Git Go Hbase History Hive Hiveql How Html Idioms Insertion Installing Ios Java Joomla Js Kafka Kali Laravel Logical Machine Matlab Matrix Mongodb Mysql One Opencv Oracle Ordering Os Pandas Php Pig Pl Postgresql Powershell Prepositions Program Python React Ruby Scala Selecting Selenium Sentence Seo Sharepoint Software Spellings Spotting Spring Sql Sqlite Sqoop Svn Swift Synonyms Talend Testng Types Uml Unity Vbnet Verbal Webdriver What Wpf

TheDeveloperBlog.com

JavaScript Debugging

JavaScript Debugging

JavaScript Debugging Example

Using console.log() method

Using debugger keyword

Related Links:

.Net

Java

Related Links