Before You Enter In React Developer, 10 Things You Should Know.

1. Numbers : Numbers is most important thing in javaScript Language. JavaScript Numbers always follow 64-bit format IEEE 754 values.
   You can use some built in function on JavaScript Numbers like as parseFloat(), parseInt(). Are you know to clear idea of javaScript Numbers, have to known NaN(Not a Number), Infinity and -Infinity.

2. Strings : Real life we use many times of Unicode characters its called in javaScript is Strings. We can find length of a string, use the built-in (length) property. Basically, JasvaScript strings are primitive values, created from liters. But strings can also be defined with the keyword (new).

3. Variables : Where we store data values its called JasvaScript Variables. Its declared var keyword before 2015. And came ES6 it declare let or const. If value is changeable it takes let otherwise const.

4. Operators : JavaScript Language have some
reminder Operators such as +, -, *, /, and % . And value assign opertaor =, +=, -=.
JavaScript have some Comparison Operators :

== equal to, ===equal value and equal type, !=not equal, !==not equal value or not equal type, >greater than, <less than, >=greater than or equal to, <=less than or equal to, ?ternary operator.

5. Control structures : JavaScript has a cortrol structures that is very helpful to developer like 3as if, else, while loops, for loops, switch case.

6. JavaScript Objects : Objects are variable too. but objects can contain many values. We define a javaScrript object with an object liter. objectName and propertyName accessing object Properts.

7. Arrays : If we want store multiple values in a single variable, use javaScropt arrays. Some built-in function used to arrays make dev life easier like pop(), push(), shift(), unshift(), splice(), slice(), concat().

8. Functions : JavaScript Core component is function. JS functions are defined with the function keyword. Nowadayes Arrow function makes a developer life very easier.

9. Custom objects : JavaScript is a object-oriented programming language. Objects are collection of data. JavaScript is prototype based language.

10. Other types keyword : We have face some special keywords like as null, undefined, false , true so we should konw to clear idea in this keyword.