# Basic of JavaScript

In ES6 JavaScript has 6 types of Data:

Number, String, Boolean, Function, Object, Symbol

**Number:**

JavaScript Numbers are Always 64-bit Floating Point. We can convert a string to an integer using the built-in **parseInt() **function.

Similarly we can parse floating point numbers using the built-in **parseFloat() **function.

A special value is called **NaN **is returned if the string is non-numerical. We can test **NaN **using the built-in **Number.isNaN() **function.

JavaScript also has the special values **Infinity. **They are **0** and **1.**

## Strings:

JavaScript strings are sequences of Unicode characters. Each Unicode character is represented by either 1 or 2 code units.

To find the length of strings, **length **property is used.

**slice() = **This method extracts a section of a string and returns it as a new string. Example:

**split() = **This method divides a string into an ordered list of substrings, puts these substrings into an array, and returns the array. Example:

## Boolean:

Boolean types has two possible values, true and false.

**False: **False, 0, empty strings (“”), NaN, null, and undefined all become false

**True: **All other values become true

## Function:

A function definition consists of the function keyword.

**Object:**

The object class represents one of the JavaScript data types. It is used to store various keyed collections and more complex entities.

## Symbol:

Every **symboll() **call is guaranteed to return a unique Symbol. Every **symbol.for(“key”) **call will always return the same Symbol for a given value of **"key”. **When **symbol.for(“key”) **is called, if a Symbol with the given key can be found in the global Symbol registry, that Symbol is returned. Otherwise, a new Symbol is created, added to the global Symbol registry under the given key, and returned.

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## Math:

**Math.max() = **This function returns the largest number from the input number. Example:

**Math.min() = **This function returns the lowest number from the input number. Example:

**Math.random() = **This function returns the random number from the input number. Example:

## Array

**every() = **This method tests all elements in the array pass the test implemented by the provided functions. It return the **Boolean** value. Example:

**find() = **Return the first element in the provided array that satisfies the provided testing function. Example:

**forEach() = **It provide all array element once. Example: