JavaScript if-else example code for beginners

📚 Quick Study Guide

• 🔑 `if` Statement: Executes a block of code if a specified condition is true.
• 🚪 `else` Statement: Executes a block of code if the same condition is false.
• ⛓️ `else if` Statement: Specifies a new condition to test if the first condition is false.
• ⚖️ Conditional Expressions: Use comparison operators (e.g., `==`, `!=`, `>`, `<`) to create conditions.
• 🧱 Code Blocks: Blocks of code within `if`, `else if`, and `else` are enclosed in curly braces `{}`.
• ✍️ Syntax: javascript if (condition) { // code to execute if condition is true } else if (anotherCondition) { // code to execute if anotherCondition is true } else { // code to execute if all conditions are false }

Practice Quiz

1. Which keyword is used to specify a block of code to be executed, if a specified condition is true?
   1. A. `when`
   2. B. `if`
   3. C. `condition`
   4. D. `true`
2. What does the `else` statement do in an `if-else` construct?
   1. A. It specifies a new condition to test.
   2. B. It executes a block of code if the `if` condition is true.
   3. C. It executes a block of code if the `if` condition is false.
   4. D. It always executes, regardless of the `if` condition.
3. Which of the following is a valid `if-else` statement in JavaScript?
   1. A. `if condition then { // code } else { // code }`
   2. B. `if (condition) { // code } otherwise { // code }`
   3. C. `if (condition) { // code } else { // code }`
   4. D. `condition if { // code } else { // code }`
4. What is the purpose of the `else if` statement?
   1. A. To end the `if-else` construct.
   2. B. To specify a new condition to test if the preceding `if` condition is false.
   3. C. To execute code regardless of any conditions.
   4. D. To define a default condition.
5. What will the following code output? javascript let x = 10; if (x > 5) { console.log("Greater than 5"); } else { console.log("Less than or equal to 5"); }
   1. A. "Less than or equal to 5"
   2. B. "Greater than 5"
   3. C. Error
   4. D. Nothing
6. Which operator is commonly used in the condition part of an `if` statement to check for equality?
   1. A. `=`
   2. B. `==`
   3. C. `===`
   4. D. Both B and C
7. What happens if the condition in an `if` statement is always false?
   1. A. The `else` block, if present, will execute.
   2. B. The code inside the `if` block will execute.
   3. C. An error will occur.
   4. D. The program will crash.