JavaScript: Conditional Statements

Question 1

What is the syntax for an “if statement?”

Answer 1

const hungerLevel = 50;
const isLunchTime = true;
const lunchBill = 11;
…

Evaluates to true so “Hungry” is logged:
if (hungerLevel >= 50) {
console.log(“Hungry!”);
}

Evaluates to false so nothing is logged:
if (hungerLevel < 50) {
console.log(“I’m full!”);
}

Steps:
To create an if statement in JavaScript, follow these steps:
1. Begin the if statement with the if keyword.
2. Inside the parentheses (), add a condition that evaluates to true or false.
3. If the condition is true, execute the code inside the curly braces {}.
4. Optionally, add an else statement after the if statement to specify code that will execute if the condition is false.

Question 2

What is the syntax for an “else statement?”

Answer 2

const hungerLevel = 50;
const isLunchTime = true;
const lunchBill = 11;
…

Evaluates to true so “Lunchtime” is logged:
if (isLunchTime === true) {
console.log(“Lunchtime”);
} else {
console.log(“Not Lunchtime”);
}

Question 3

Shorthand for the following:

if (isLunchTime === true) {
console.log(“Lunchtime”);
} else {
console.log(“Not Lunchtime”);
}

Answer 3

if (isLunchTime) {
console.log(“Lunchtime!!”);
} else {
console.log(“Not Lunchtime!!”);
}

Question 4

Example of how “Else if” allows you to test more than one condition

Answer 4

The first condition is false, so the second condition is evaluated. Logs “Cost Rating: $$”

if (lunchBill < 10) {
console.log(“Cost Rating: $”);
} else if (lunchBill >= 10 && lunchBill < 15) {
console.log(“Cost Rating: $$”);
} else {
console.log(“Cost Rating: $$$”);
}