JavaScript Ninja

If-Else Statements

In this chapter, we will explore the concept of if-else statements in JavaScript. If-else statements allow us to make decisions in our code based on certain conditions. This is a fundamental concept in programming that enables us to control the flow of our programs.

Understanding If-else Statements

An if-else statement evaluates a condition and executes a block of code if the condition is true. If the condition is false, it can execute an alternative block of code. This is how we can make our programs respond differently to different situations.

Here's the basic structure of an if-else statement:

const condition = true

if (condition) {

console.log("Condition is true")

} else {

console.log("Condition is false")

}


              123456
            
const condition = true
if (condition) {
  console.log("Condition is true")
} else {
  console.log("Condition is false")
}

The "!" Symbol

The "!" symbol is used to negate a boolean expression. If a condition is true, using "!" will make it false, and vice versa. This can be very useful when you want to execute code only when a condition is not met.

For example:

const condition = false

if (!condition) {

console.log("Condition is false")

}


              1234
            
const condition = false
if (!condition) {
  console.log("Condition is false")
}

Example

Let's look at an example that uses if-else statements to help our ninja collect all the sushi on the map. The ninja will move around the grid, picking up sushi while avoiding walls.

ninja.js

function ninjaController(ninja) {

while (!(ninja.objectUp() === "wall" && ninja.objectRight() === "wall")) {

if (ninja.objectRight() === "wall") {

ninja.goUp();

ninja.pickSushi();

}

ninja.goRight();

ninja.pickSushi();

}

}

In this example, the ninja will continue to move and pick up sushi until it encounters walls both above and to the right. The if-else statement checks if there is a wall to the right. If there is, the ninja moves up and picks up sushi. Otherwise, it moves to the right and picks up sushi.

Tarefa

Swipe to start coding

Solução

function ninjaController(ninja) {

for (let i = 0; i < 8; i++) {

ninja.goRight();

if (ninja.objectRight() === "wall") {

if (ninja.objectDown() === "wall") {

ninja.goUp();

} else {

ninja.goDown();

}

}

}

ninja.pickSushi();

}

Tudo estava claro?

Obrigado pelo seu feedback!

Seção 5. Capítulo 1

ninja.js

function ninjaController(ninja) {

// Write your code below

}

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JavaScript Ninja

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1. Basic Controls

In the "Basic Controls" section, you'll be introduced to the foundational features of JavaScript through the engaging Ninja Game. You'll learn how to use JavaScript commands to control your ninja's movements and interactions on the grid, mastering essential functions like moving, picking up, and placing sushi. Through hands-on practice, you'll apply these skills to solve fun challenges, reinforcing your understanding of JavaScript's basic capabilities.

Practice. Collect Side Sushi

Practice. Collect Diagonal Sushi

Practice. Bypass an Obstacle

2. Advanced Controls

Movement Challenge

Practice. Pick and Move to the Corner

Practice. Move Sushi to the Center of the Box

Practice. Pick and Hide Sushi

3. Functions

In the "Functions" section, you'll delve into the powerful JavaScript feature of creating and utilizing functions to streamline your code. You'll learn how to write functions to perform specific tasks, enhancing code reusability and clarity. By practicing decomposition, you'll break down complex problems into simpler functions, mastering the art of organized and efficient coding.

Using Functions

Writing Functions

Functions Practice. Collect Pits

Functions Practice. Make Diagonals

Decomposition Practice. Collect Angles

Decomposition Practice. Move Columns

Decomposition Practice. Collect Sections

4. Loops

In the "Loops" section, you'll explore the essential JavaScript feature of loops, which allows you to execute repetitive tasks efficiently. You'll learn to implement both for loops and while loops, gaining the ability to automate actions and iterate over sequences. By mastering nested loops, you'll tackle more complex scenarios, enhancing your ability to write concise and powerful code.

For Loops Practice

5. If-Else Statements

In the "If-Else Statements" section, you'll learn how to use JavaScript's conditional logic to make decisions within your code. You'll explore how if-else statements allow your ninja to respond dynamically to different scenarios, enabling more intelligent and adaptable behavior. Through practical exercises, you'll apply these concepts to solve challenges, enhancing your ability to write responsive and decision-driven code.

If-Else Statements

If-Else Statements Practice. Roll the Sushi

If-Else Statements Practice. Clear the Storage

If-Else Statements Practice. Follow the Sushi Snake

6. Challenges

In the "Challenges" section, you'll apply your JavaScript skills to tackle a series of engaging and complex problems. These challenges will test your understanding of loops, functions, and conditional logic as you guide your ninja to align columns, build letters, and traverse intricate patterns. By solving these puzzles, you'll refine your coding abilities and gain confidence in applying JavaScript to creative and real-world scenarios.

Challenge: Build letter K

Challenge: Build letter E

Challenge: Traverse Spiral

Challenge: Align two columns