No One Talk About JavaScript This Topic
1. Primitive Value
javascript have some primitive values as like number, string, boolean, null, undefined etc. and javascript have manipulated value like object, function
2. typeOf()
this method used when we need to values data type. occasionally we need to what is the data type of this values.
3. Coding Style
This is very important for every developer. it is help for others developer to understand code easily. for example looking the picture attentionly
4. Comment
Comment is very very important for any developer because when your code see another developer then developer can’t easily this code if you on include comment before code. if you write a code before you write a comment this code why you write, i mean this code works. you can write single line comment and other sometime one line comment not enough for this code understand
5. Block Scope
when you write any loop, if/else or function inside {} , then it is a block scope. let and const depend block scope its attitude into a block scope one think, and out side another think.
you can’t access block scope element outside this block scope but you can access in block scope anything outside block scope(global)
6.Arrow Function
arrow function come to javascript es6 version. it is very simple to call a function. arrow function call many type. you call one line and also multiple line which you need. when you call arrow function don’t need name.
if you a call arrow function one line then you don’t need return or if you call arrow function then must me need return.
7. spread Operator
this is come from javascript es6.before es6 come if you need to any array all element then you need loop on array and push new array and but after es6 come dont’t need to loop on array. its look […] .
8. Default Parameter
when we declare function and use a parameter. when the function we call then we don’t pass parameter value the then parameter value is undefined but es6 change the problem after es6 now we can use parameter backup value. For Example
9. Ternary operator
ternary operator easy to our life. we can use condition using if/else multiple line but ternary operator we use one line.
10. Map
map is a loop. this loop use only an array. when this loop continue in an array we get a result one by one element.