JavaScript

JavaScript is a scripting language. javascript syntax based on java and c.

Types of JavaScript:

1.Boolean

JavaScript Boolean only has two values, true and false.

Ex: let (5>2) //true

Let (5<0) //false

2. Numbers

Numbers can be written with or without decimals

Ex: var a = 2.50 //with decimals

Var b = 20 //without decimals

3. Strings

Strings can be any text inside double or single quotation.even a whiteSpace is also a string.

Ex: let string = “Moyuri Akther”;

Let result = string.length;

Output = 13;

Methods of strings:

1. charAt() Method: charAt method returns index position

Ex: let string = “Moyuri”

string.charAt(3)

Output u

1. concat() Method: Concat joint two or more strings and return a new string

Ex: let string1 = “Moyuri”

Let string2 = “Akther”

Let string3 = string1.concat(‘ ’, string2);

1. includes() Method: To find out if one string is in another string use includes() method.

Ex: let string1 = “Moyuri eat rice”;

Let word = “eat”;

console.log(string.includes(‘eat’)); //true

1. endsWith: This method lets you determine if one string ends with another.

Ex: let string1 = “Moyuri eat rice”;

console.log(string.endsWith(rice)); //true

4.Symbol

5.Object

6.Function

Functions are core components of javascript.we can call a function with a parameter or without parameter or more than expected parameter.

Ex: Add(); // without parameter

Add(4, 6) // with parameter

Add(3, 5, 2) // more then expected parameter

7.Array:

In JavaScript, arrays are one type of special object. An array can hold more than one value at a time. Length is a special property of the array.

Ex: var names = [‘Moyuri’, ‘Rimi’, ‘Riva’];

Ex2: var names[0] = ‘Moyuri’;

var names[1] = ‘Rimi’;

var names[2] = ‘Riva’;

9.Date

10.RegExp

Variables: JavaScript has three types of variables var, let, and const

Var: The value of any type of variable can be determined with var

Let: Let Declare the value of variables that may change

Const: Variables whose value will never be changed or redefined are declared by const

Operators: javascript operators are +, -, *, /, %

Comparisons: JavaScript comparisons are <, >, <=, >= , ==, ===, !=, !===

Determines the value by double equals. Triple equal used for comparison.

JavaScript Math:

Math.round(): math.round() returns the nearst integer number.

Ex: Math.round(4.3) // output is 4

Math.round(4.8) //output is 5

Math.ceil(): Math.ceil() converts the decimal number into the integer above.

Ex: Math.ceil(4.3) // output is 5

Math.ceil(4.8) //output is 5

Math.floor(): Math.floor() converts the decimal number into the integer below.