If statement in Javascript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of an if statement in JavaScript?

An if statement lets the program decide to run some code only if a condition is true. It helps the program make choices.

beginner

Write the basic syntax of an if statement in JavaScript.

The basic syntax is:<br>

if (condition) {<br>  // code to run if condition is true<br>}

beginner

What happens if the condition in an if statement is false?

If the condition is false, the code inside the if block does not run. The program skips it and continues.

beginner

How do you add an alternative action if the if condition is false?

You use an else block after the if block. It runs when the if condition is false.<br>

if (condition) {<br>  // runs if true<br>} else {<br>  // runs if false<br>}

intermediate

Can you check multiple conditions with if statements? How?

Yes, by using else if blocks between if and else. It checks conditions one by one until one is true.<br>

if (cond1) {<br>  // code<br>} else if (cond2) {<br>  // code<br>} else {<br>  // code<br>}

What does this code do?<br>

if (5 > 3) { console.log('Yes'); }

A Prints 'Yes' because 5 is greater than 3

B Prints nothing because 5 is not greater than 3

C Gives an error

D Prints 'No'

5 is greater than 3, so the condition is true and 'Yes' is printed.

Which keyword runs code when the if condition is false?

A else

B elseif

C then

D when

The else block runs when the if condition is false.

What will this code print?<br>

if (false) { console.log('A'); } else { console.log('B'); }

A A

B Nothing

C B

D Error

The condition is false, so the else block runs and prints 'B'.

How do you check more than two conditions in an if statement?

A Use multiple <code>else</code> blocks

B Use multiple <code>else if</code> blocks

C Use <code>switch</code> only

D Use multiple <code>if</code> without else

You use else if blocks to check multiple conditions one after another.

What is the output of:<br>

if (10 === '10') { console.log('Match'); } else { console.log('No match'); }

A Match

B Undefined

C Error

D No match

The triple equals === checks type and value. Number 10 is not the same type as string '10', so condition is false.

Explain how an if statement works in JavaScript and give a simple example.

Think about how you decide to do something only if a condition is true.

Describe how to use else if and else to handle multiple choices in JavaScript.

Imagine choosing between many options, checking one by one.