Javascript: Operators and Expression

OPERATORS

1. arithmetic operators
+ (addition)
- (subtraction)
/ (division)
* (multiplication)
% (modulus)

2. ++ (increment)
-- (decrement)
+= (eg: a+= b means a = a+b;)
-= (eg: a-=b means a = a-b;)
>, <, >=, <= (Relation operators)

3. = (assignment operator)
== (equality operator, value check)
=== (check value and data type)
eg if(95 == '95'){
console.log('hi');
}

matched
eg if(95 === '95'){
console.log('hi');
}
does not match, value 95 correct but number and string data type

4. logical operators
! (logical not)
var a = true;
console.log(a);
&& (logical and both value should be true)
a && b means a and b should be true

|| (logical or)
either value should be true
a || b means a or b should be true

? (ternary operator)
a?a:b means a takes a value if its there otherwise takes b value

" + " , " , " (concatenate operator)
Code is a set of special instructions to tell the computer what tasks to performs.
statement is a group of words, numbers and operations that performs a specific tasks.
eg: a = b * 2;

Expression: statements are made up of one or more expressions.
eg: a is a variable, 2 is literal value expression, b*2 is arithmetic expression, a = b * 2 has assignment operator

Example in console
var a = 21;
var b = 12;
a*b
output: 252

Javascript inbuild function
example: alert('hi); confirm('Are you sure')

Converting between types
If you have a number but need to print it on the screen, you need to convert the value to the String, this conversion is called Coercion

Implicit Coercion: conversion by js itself
Example
if(95 == '95'){
console.log('hi');
}

Explicit Coercion: conversion by us
Example
var a = '21';
a output '21'
Number(a);

Comment
(single comment)
/* multi line comment */
Block of code (opening and closing block)
if(){
if block
}else{
else block
}