JavaScript if…else Statements

• Conditional Execution: if...else statements are used to conditionally execute blocks of code based on whether a specified condition is true or false.

• Syntax:

  JavaScript

   

  if (condition) {
    // Code to be executed if the condition is true
  } else {
    // Code to be executed if the condition is false
  }
  

• Example:

  Code snippet

   

  const age = 25;
  
  if (age >= 18) {
    console.log("You are an adult."); 
  } else {
    console.log("You are a minor.");
  }
  

• else if: You can chain multiple conditions using else if statements:

  JavaScript

   

  const grade = 85;
  
  if (grade >= 90) {
    console.log("Excellent!");
  } else if (grade >= 80) {
    console.log("Great job!");
  } else if (grade >= 70) {
    console.log("Good work!");
  } else {
    console.log("Needs improvement.");
  }
  

• Logical Operators: Often used within conditions:

  • && (AND): Both conditions must be true.
  • || (OR): At least one condition must be true.
  • ! (NOT): Reverses the truth value of a condition.
  JavaScript

   

  if (age >= 18 && age <= 65) { 
    // Code for adults between 18 and 65
  }
  

• Ternary Operator: A shorthand for simple if...else statements:

  JavaScript

   

  const isAdult = (age >= 18) ? true : false; 
  

if...else statements are crucial for controlling the flow of your JavaScript programs, allowing you to make decisions and execute different code blocks based on specific conditions.