javascript quick Cheat sheet

Variables:

JAVA SCRIPT

// Declare a variable with let
let x = 5;

// Declare a constant with const
const y = 10;

// Declare a variable without assigning a value
let z;

Data types:

JAVA SCRIPT

 // Number
let a = 5;
let b = 3.14;

// String
let c = "Hello";
let d = 'World';

// Boolean
let e = true;
let f = false;

// Undefined
let g;

// Null
let h = null;

// Object
let i = { name: "John", age: 30 };

// Array
let j = [1, 2, 3, 4];

Operators:

JAVA SCRIPT 

 // Arithmetic operators
let a = 5 + 2; // 7
let b = 5 - 2; // 3
let c = 5 * 2; // 10
let d = 5 / 2; // 2.5
let e = 5 % 2; // 1

// Comparison operators
let f = 5 == 5; // true
let g = 5 === '5'; // false
let h = 5 != 5; // false
let i = 5 !== '5'; // true
let j = 5 > 2; // true
let k = 5 < 2; // false
let l = 5 >= 5; // true
let m = 5 <= 2; // false

// Logical operators
let n = true && false; // false
let o = true || false; // true
let p = !true; // false  
 

Conditional statements:

JAVA SCRIPT 

 // If statement
let a = 5;
if (a > 2) {
console.log("a is greater than 2");
}

// If-else statement
let b = 1;
if (b > 2) {
console.log("b is greater than 2");
} else {
console.log("b is less than or equal to 2");
}

// If-else if-else statement
let c = 0;
if (c > 0) {
console.log("c is positive");
} else if (c < 0) {
console.log("c is negative");
} else {
console.log("c is zero");
} 

Loops:

JAVASCRIPT

// For loop
for (let i = 0; i < 5; i++) {
console.log(i);
}

// While loop
let j = 0;
while (j < 5) {
console.log(j);
j++;
}

// Do-while loop
let k = 0;
do {
console.log(k);
k++;
} while (k < 5);

// For-in loop (used to loop over properties of an object)
let person = { name: "John", age: 30 };
for (let key in person) {
console.log(key + ": " + person[key]);
}

// For-of loop (used to loop over elements of an array)
let arr = [1, 2, 3];
for (let value of arr) {
console.log(value);
}

Functions:

JAVASCRIPT 

// Function declaration
function add(a, b) {
  return a + b;
}

// Function expression
let multiply = function(a, b) {
  return a * b;
};

//