Try–catch block in Javascript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to catch errors using a try-catch block.

Javascript

try {
  console.log('Start');
  [1]
} catch (error) {
  console.log('Error caught');
}

Drag options to blanks, or click blank then click option'

Athrow new Error('Oops!')

Bconsole.log('No error')

Creturn 'Done'

Dbreak

Attempts:

3 left

💡 Hint

Common Mistakes

Using console.log instead of throw inside try.

Using break outside loops or switch.

The throw statement inside try causes an error that is caught by catch.

2fill in blank

medium

Complete the code to handle an error and print its message.

Javascript

try {
  JSON.parse('invalid json');
} catch ([1]) {
  console.log([1].message);
}

Drag options to blanks, or click blank then click option'

Ae

Berr

Cexception

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inside catch and console.log.

Omitting the catch parameter.

The catch block receives the error object, here named 'error', to access its message.

3fill in blank

hard

Fix the error in the try-catch syntax.

Javascript

try {
  let result = 10 / 0;
  console.log(result);
} [1] (e) {
  console.log('Error:', e);
}

Drag options to blanks, or click blank then click option'

Aerror

Bfinally

Ccatch

Dexcept

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'except' which is Python syntax.

Using 'error' which is not a keyword.

The correct keyword to catch errors is 'catch'.

4fill in blank

hard

Fill both blanks to rethrow an error after catching it.

Javascript

try {
  throw new Error('Fail');
} [1] (err) {
  console.log('Caught:', err.message);
  [2] err;
}

Drag options to blanks, or click blank then click option'

Acatch

Bthrow

Cfinally

Dreturn

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'finally' instead of 'catch'.

Using 'return' instead of 'throw' to rethrow.

Use 'catch' to handle the error and 'throw' to rethrow it.

5fill in blank

hard

Fill all three blanks to parse JSON safely and handle errors.

Javascript

function safeParse(json) {
  try {
    return JSON.[1](json);
  } catch ([2]) {
    console.log('Invalid JSON:', [3].message);
    return null;
  }
}

Drag options to blanks, or click blank then click option'

Aparse

Berror

Ce

Dexception

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method name instead of parse.

Using different variable names inside catch and console.log.

Use JSON.parse to parse JSON, and catch block parameter 'e' to handle errors.