"I am Saqib Jahangir. A passionate vlogger, software engineer, trainer and avid traveler with a deep love for exploring the hidden gems of our beautiful planet. With a strong foundation in Application Development, Application Architecture & Database Design and Product Management, I bring over a decade of hands-on experience building secure, scalable, and resilient web applications for a diverse range of industries."

Error Handling in Javascript

 

In JavaScript, things don’t always go as planned—network requests fail, variables are undefined, APIs return unexpected data. Error handling helps us detect and manage these problems so they don’t crash the entire application or cause strange behavior.

The try...catch Statement

try...catch lets you run code and handle errors without stopping the program.

try {
    let data = JSON.parse('{"name": "Alice"}');
    console.log(data.name);
} catch (error) {
    console.error("Something went wrong:", error.message);
}

Adding finally

The finally block always runs—useful for cleanup tasks.

try {
    console.log("Connecting to server...");
    throw new Error("Connection failed!");
} catch (error) {
    console.error("Error:", error.message);
} finally {
    console.log("Closing connection...");
}

Throwing Custom Errors

You can create your own errors with throw.

function checkAge(age) {
    if (age < 18) {
        throw new Error("You must be 18 or older.");
    }
    return "Access granted";
}
 
try {
    console.log(checkAge(15));
} catch (error) {
    console.error(error.message);
}

Error Handling in Promises

For Promises, use .catch():

fetch("https://api.example.com/data")
    .then(response => response.json())
    .then(data => console.log(data))
    .catch(error => console.error("Error fetching data:", error));

Error Handling with async/await

With async/await, wrap code in try...catch.

async function getData() {
    try {
        let response = await fetch("https://api.example.com/data");
        let data = await response.json();
        console.log(data);
    } catch (error) {
        console.error("Error fetching data:", error);
    }
}
 
getData();

 

Popular Posts

Operators (Arithmetic, Comparison, Logical)

  Operators in PHP are symbols that perform operations on variables and values. They are essential for performing calculations, comparing values, and making logical decisions in your code. PHP supports several types of operators, including arithmetic, comparison, and logical operators. Arithmetic Operators Arithmetic operators are used to perform basic mathematical operations. Example: <?php $a = 10; $b = 3;   echo $a + $b; // 13 echo $a - $b; // 7 echo $a * $b; // 30 echo $a / $b; // 3.3333 echo $a % $b; // 1 (modulus) echo $a ** $b; // 1000 (exponentiation) ?> Comparison Operators Comparison operators are used to compare two values. They return true or false . Example: <?php $x = 5; $y = 10;   var_dump($x == $y);   // false var_dump($x != $y);   // true var_dump($x === $y); // false (checks value and type) var_dump($x !== $y); // true var_dump($x > $y);    // false var_dum...
Read more

Functions (Built-in & User-defined)

  Functions in PHP are blocks of code designed to perform a specific task. They help make code reusable, organized, and easier to maintain. PHP provides built-in functions for common tasks, and also allows you to create your own user-defined functions . Built-in Functions PHP has hundreds of built-in functions that perform predefined operations such as string manipulation, mathematical calculations, and array handling. Example (Built-in Functions): <?php // String length echo strlen("Hello World"); // Outputs: 11   // Find maximum value in an array echo max(10, 20, 30); // Outputs: 30   // Convert string to uppercase echo strtoupper("php is awesome"); // Outputs: PHP IS AWESOME ?> User-defined Functions You can create your own functions to execute code whenever needed. This helps reduce repetition and makes programs easier to read. Syntax: function functionName($parameter1, $parameter2) {     // Code to...
Read more