JavaScript Function: Validate integer parameters with custom Error

JavaScript Error Handling: Exercise-1 with Solution

Throw Error for Non-Integer

Write a JavaScript function that takes a number as a parameter and throws a custom 'Error' if the number is not an integer.

Sample Solution:

JavaScript Code:

// Define a function named validateInteger which takes a parameter 'number'
function validateInteger(number) 
{
  // Check if the given number is not an integer using Number.isInteger() method
  if (!Number.isInteger(number)) 
  {
    // If the number is not an integer, throw an error with a specific message
    throw new Error('Invalid number. Please input an integer.');
  }
  // Log a message indicating that the number is valid
  console.log('Number is valid:', number);
}

// Example usage:
try {
  // Call validateInteger function with an integer argument (12)
  validateInteger(12); // Valid integer
  // Call validateInteger function with a non-integer argument (2.12)
  validateInteger(2.12); // Throws an error
} catch (error) {
  // Catch any errors thrown by the validateInteger function and log the error message
  console.log('Error:', error.message);
}

Output:

"Number is valid:"
12
"Error:"
"Invalid number. Please input an integer." 

Note: Executed on JS Bin

Explanation:

In the above function, the "Number.isInteger()" method is used to check if the given number is an integer. If it's not an integer, the program throws a custom "Error" with the message "Invalid number. Please input an integer." If the number is valid, the program logs a success message.

In the example usage, we demonstrate how the function works by calling it with both a valid integer (42) and an invalid number (3.14). The try-catch block catches and handles any thrown error, and the error message is logged to the console.

Flowchart:

Live Demo:

See the Pen javascript-error-handling-exercise-1 by w3resource (@w3resource) on CodePen.

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