Understanding Conditionals

Conditionals are statements that allow you to make decisions and execute different blocks of code based on whether certain conditions are true or false. Conditionals are a fundamental concept that enables your code to respond dynamically to various situations.

1. Making Decisions

Conditionals are used to create decision-making structures in your code. They enable your program to choose different paths of execution based on whether specific conditions are met.

2. If Statements

The most basic form of conditional is the if statement. It evaluates a condition and, if true, executes a specified block of code. If false, the code inside the block is skipped.

if (condition) {
  // Code to execute if condition is true
}
  

3. Else Statements

The else statement provides an alternative block of code to execute when the condition is false, covering both “if” and “else” scenarios.

if (condition) {
  // Code to execute if condition is true
} else {
  // Code to execute if condition is false
}
  

4. Else-If Statements

Else if statements evaluate additional conditions when you have multiple conditions to check, executing the block of the first true condition.

if (condition1) {
  // Code to execute if condition1 is true
} else if (condition2) {
  // Code to execute if condition2 is true
} else {
  // Code to execute if no conditions are true
}
  

5. Switch Statements

Switch statements test a variable against multiple values and execute different code blocks based on the matching value.

switch (variable) {
  case value1:
    // Code to execute for value1
    break;
  case value2:
    // Code to execute for value2
    break;
  default:
    // Code to execute if no cases match
}
  

6. Ternary Operator

In some languages like JavaScript, the ternary operator (condition ? expressionIfTrue : expressionIfFalse) provides a shorthand for simple conditional expressions.

var result = (condition) ? "Value if true" : "Value if false";
  

Conditionals are a powerful tool for controlling the flow of your program based on different situations. They allow your code to adapt and respond to changing conditions, making your applications more dynamic and interactive.

JavaScript Conditional Examples

1. If Statement

var age = 20;

if (age >= 18) {
  console.log("You are an adult.");
}
  

2. If-Else Statement

var temperature = 25;

if (temperature > 30) {
  console.log("It's hot outside.");
} else {
  console.log("It's not too hot.");
}
  

3. Else-If Statement

var grade = 85;

if (grade >= 90) {
  console.log("A");
} else if (grade >= 80) {
  console.log("B");
} else if (grade >= 70) {
  console.log("C");
} else {
  console.log("F");
}
  

4. Switch Statement

var day = "Monday";

switch (day) {
  case "Monday":
    console.log("It's the start of the week.");
    break;
  case "Friday":
    console.log("It's the end of the week.");
    break;
  default:
    console.log("It's a regular day.");
}
  

5. Ternary Operator

var isMorning = true;
var greeting = isMorning ? "Good morning!" : "Hello!";
console.log(greeting);