J078 Custom Error Handling in JavaScript

A task aimed at understanding how to throw and handle custom errors in JavaScript based on specific conditions.

Create a file named app.js and adhere to the following guidelines:

• Start with “use strict”.
• Create a function named printString that accepts a single parameter, str.
• The function should check the length of str.
• If the length of str is less than 5 characters, throw a new error with the message “String too short”.
• If the string length is adequate, print the string to the console.

Testing the Function

• Call printString with various strings to test the functionality.
• Use a try-catch block to handle any errors thrown by the function.
• In the catch block, log the error message to the console.
• Include at least one string that is shorter than 5 characters to trigger the error.

Reflecting on Custom Errors

• Understand how throwing custom errors based on specific conditions can enhance the robustness of your code.
• Notice how the program handles both successful and error scenarios.

Example Usage

"use strict";

function printString(str) {
    if (str.length < 5) {
        throw new Error("String too short");
    }
    console.log(str);
}

try {
    printString("Hello World"); // Prints "Hello World"
} catch (error) {
    console.log(error.message);
}

try {
    printString("Hi"); // Error caught here
} catch (error) {
    console.log(error.message);
}

try {
    printString("Welcome"); // Prints "Welcome"
} catch (error) {
    console.log(error.message);
}