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Conditional Statements and Loops in JavaScript

bookelse and else if

When you need your code to make decisions based on more than just a simple yes or no, you use branching logic. This means your program can follow different paths depending on what's happening. A great way to picture this is to imagine a traffic light. When you approach a traffic light, you have to make a decision.

  • If the light is red, you stop;
  • If it's yellow, you get ready to stop;
  • If it's green, you go.

In JavaScript, you can handle these different possibilities using if, else if, and else statements. This lets your code respond to many situations, not just two.


              
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let light = "yellow";

if (light === "red") {
  console.log("Stop!");
} else if (light === "yellow") {
  console.log("Get ready to stop.");
} else if (light === "green") {
  console.log("Go!");
} else {
  console.log("Unknown signal.");
}
copy

              
1234567891011

            
let light = "green";

if (light === "red") {
  console.log("Stop!");
} else if (light === "yellow") {
  console.log("Get ready to stop.");
} else if (light === "green") {
  console.log("Go!");
} else {
  console.log("Unknown signal.");
}
copy
question-icon

Match each traffic light color to the correct message printed by the code.

- red:- yellow:- green:

Click or drag`n`drop items and fill in the blanks

Tutto è chiaro?

Come possiamo migliorarlo?

Grazie per i tuoi commenti!

Sezione 1. Capitolo 4

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Suggested prompts:

Can you explain how the `else if` statement works in this example?

What happens if the value of `light` is something other than "red", "yellow", or "green"?

Can you show how to add more conditions to this branching logic?

bookelse and else if

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When you need your code to make decisions based on more than just a simple yes or no, you use branching logic. This means your program can follow different paths depending on what's happening. A great way to picture this is to imagine a traffic light. When you approach a traffic light, you have to make a decision.

  • If the light is red, you stop;
  • If it's yellow, you get ready to stop;
  • If it's green, you go.

In JavaScript, you can handle these different possibilities using if, else if, and else statements. This lets your code respond to many situations, not just two.


              
1234567891011

            
let light = "yellow";

if (light === "red") {
  console.log("Stop!");
} else if (light === "yellow") {
  console.log("Get ready to stop.");
} else if (light === "green") {
  console.log("Go!");
} else {
  console.log("Unknown signal.");
}
copy

              
1234567891011

            
let light = "green";

if (light === "red") {
  console.log("Stop!");
} else if (light === "yellow") {
  console.log("Get ready to stop.");
} else if (light === "green") {
  console.log("Go!");
} else {
  console.log("Unknown signal.");
}
copy
question-icon

Match each traffic light color to the correct message printed by the code.

- red:- yellow:- green:

Click or drag`n`drop items and fill in the blanks

Tutto è chiaro?

Come possiamo migliorarlo?

Grazie per i tuoi commenti!

Sezione 1. Capitolo 4
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