Javascript Cheatsheet | Javascript Explain Very East Steps

Here is a JavaScript cheat sheet that you can use as a quick reference guide:

Variables

Declare variables using let or const:

let x;  // declares a variable called x
const y = 5;  // declares a constant called y and assigns it the value 5

Data Types

JavaScript has the following data types:

• String (e.g. "hello")
• Number (e.g. 42)
• Boolean (true or false)
• Null (a special value that represents the absence of a value)
• Undefined (a special value that represents a variable that has not been assigned a value)
• Object (a collection of key-value pairs)
• Symbol (a unique and immutable data type)

Operators

JavaScript has the following operators:

• Arithmetic operators (e.g. +, -, *, /, %)
• Comparison operators (e.g. ==, !=, <, >, <=, >=)
• Logical operators (e.g. &&, ||, !)

Conditional Statements

Use if statements to execute different code blocks based on a condition:

if (x > y) {
  console.log("x is greater than y");
} else if (x < y) {
  console.log("x is less than y");
} else {
  console.log("x is equal to y");
}

Loops

Use for loops to iterate over a block of code a specific number of times:

for (let i = 0; i < 10; i++) {
  console.log(i);  // prints 0 through 9
}

Use while loops to iterate over a block of code as long as a certain condition is true:

let i = 0;
while (i < 10) {
  console.log(i);  // prints 0 through 9
  i++;
}

Use do...while loops to execute a block of code at least once before checking a condition:

let i = 0;
do {
  console.log(i);  // prints 0 through 9
  i++;
} while (i < 10);

Functions

Declare functions using the function keyword:

function greet(name) {
  console.log("Hello, " + name);
}

greet("John");  // prints "Hello, John"

Objects

Declare objects using object literals:

const person = {
  name: "John",
  age: 30,
  speak: function() {
    console.log("Hello, my name is " + this.name);
  }
};

person.speak();  // prints "Hello, my name is John"

Arrays

Declare arrays using square brackets:

const numbers = [1, 2, 3, 4, 5];

console.log(numbers[0]);  // prints 1

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