Control Flow

Control flow statements are used to dictate the order in which code is executed. They allow for decision-making, repetition, and branching within your programs.

Conditional Statements

Conditional statements execute code blocks based on whether a specified condition is true or false.

if Statement

The if statement executes a block of code if a specified condition is true.

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

if...else Statement

The if...else statement executes one block of code if the condition is true, and another block if it is false.

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

if...else if...else Statement

This allows for multiple conditions to be checked sequentially.

if (condition1) {
    // Code if condition1 is true
} else if (condition2) {
    // Code if condition2 is true
} else {
    // Code if all previous conditions are false
}
        

switch Statement

The switch statement is used to perform different actions based on different conditions. It is often a cleaner alternative to a long series of if...else if statements when checking the value of a single variable.

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

Looping Statements

Looping statements allow you to execute a block of code repeatedly.

for Loop

The for loop is used to execute a block of code a specific number of times.

for (initialization; condition; increment) {
    // Code to execute in each iteration
}
        

for (let i = 0; i < 5; i++) {
    console.log("Iteration: " + i);
}
            

while Loop

The while loop executes a block of code as long as a specified condition is true.

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

let count = 0;
while (count < 3) {
    console.log("Count is: " + count);
    count++;
}
            

do...while Loop

The do...while loop is similar to the while loop, but it guarantees that the code block will be executed at least once, regardless of the condition.

do {
    // Code to execute at least once
} while (condition);
        

let num = 5;
do {
    console.log("This will print at least once.");
    num++;
} while (num < 5);
            

for...in Loop

The for...in loop iterates over the enumerable properties of an object.

for (const key in object) {
    // Access object[key]
}
        

for...of Loop

The for...of loop iterates over the values of an iterable object (like arrays, strings, Maps, Sets).

for (const element of iterable) {
    // Access element
}
        

const colors = ["red", "green", "blue"];
for (const color of colors) {
    console.log(color);
}
            

Branching Statements

Branching statements alter the normal flow of execution within loops or statements.

break Statement

The break statement terminates the current loop or switch statement.

continue Statement

The continue statement skips the rest of the current iteration of a loop and continues with the next iteration.

for (let i = 0; i < 5; i++) {
    if (i === 2) {
        continue; // Skips printing 'Iteration: 2'
    }
    console.log("Iteration: " + i);
}
            

Mastering control flow is fundamental to writing dynamic and responsive applications. Experiment with these statements to understand their behavior thoroughly.