Introduction

• JavaScript is a high-level, interpreted programming language.
• Primarily used for enhancing web pages, enabling interactive features.

Data Types

• Primitive Types:
  • String: Represents text (e.g., "Hello, World!").
  • Number: Represents numeric values (e.g., 42, 3.14).
  • Boolean: Represents true or false.
  • Null: Represents an intentional absence of any value.
  • Undefined: A variable that has been declared but not assigned a value.
  • Symbol: A unique and immutable value.
• Complex Types:
  • Object: A collection of properties (e.g., { name: "John", age: 30 }).
  • Array: An ordered list of values (e.g., [1, 2, 3]).

Variables

• Declared using var, let, or const:
  • var: Function-scoped or globally scoped, can be re-declared.
  • let: Block-scoped, cannot be re-declared in the same block.
  • const: Block-scoped, must be initialized and cannot be re-assigned.

Operators

• Arithmetic Operators: +, -, *, /, %
• Comparison Operators: ==, ===, !=, !==, <, >, <=, >=
• Logical Operators: && (AND), || (OR), ! (NOT)

Control Structures

• Conditional Statements:

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

• Switch Statement:

  switch (expression) {
    case value1:
      // code
      break;
    case value2:
      // code
      break;
    default:
    // code
  }

• Loops:

  • for loop:

    for (let i = 0; i < 5; i++) {
      // code
    }
  • while loop:

    while (condition) {
      // code
    }

• Functions:

  • Declared using the function keyword

    function myFunction(param1, param2) {
      // code
    }
  • Arrow functions:

    const myFunction = (param1, param2) => {
      // code
    };

Objects

• Creating an object:

  const person = {
      name: "Alice",
      age: 25,
      greet: function() {
          console.log("Hello!");
      }
  };`

Arrays

• Creating an array:

  const fruits = ["apple", "banana", "cherry"];

• Common array methods: .push(), .pop(), .shift(), .unshift(), .map(), .filter(), .reduce()