Lecture 3: Control Statements

Overview

• Control statements dictate the flow of execution in a program.
• They are essential for decision-making and iteration in programming.

Types of Control Statements

1. Conditional Statements

   • Used to perform different actions based on different conditions.
   • Common types include:
     • if statements
     • if-else statements
     • switch statements

2. Looping Statements

   • Allow code to be executed repeatedly based on a condition.
   • Common types include:
     • for loops
     • while loops
     • do-while loops

Conditional Statements

if Statement

• Syntax: if (condition) { // code to execute if condition is true }
• Example: if (x > 10) { console.log('x is greater than 10'); }

if-else Statement

• Syntax: if (condition) { // code if condition is true } else { // code if condition is false }
• Example: if (x > 10) { console.log('x is greater than 10'); } else { console.log('x is 10 or less'); }

switch Statement

• Used to execute one block of code among many choices.
• Syntax: switch (expression) { case value1: // code block break; case value2: // code block break; default: // code block }

Looping Statements

for Loop

• Used for iterating over a sequence (like an array).
• Syntax: for (initialization; condition; increment) { // code to execute }
• Example: for (let i = 0; i < 5; i++) { console.log(i); }

while Loop

• Repeats a block of code as long as a condition is true.
• Syntax: while (condition) { // code to execute }
• Example: let i = 0; while (i < 5) { console.log(i); i++; }

do-while Loop

• Executes a block of code once, and then repeats while a condition is true.
• Syntax: do { // code to execute } while (condition);
• Example: let i = 0; do { console.log(i); i++; } while (i < 5);

Summary

• Control statements are crucial for controlling the flow of execution in programs.
• Understanding how to implement conditional and looping statements is vital for programming.