JavaScript Learning Notes: Conversion and Operations

Conversions


                    let score = "hitesh"

                    console.log(typeof score);
                    console.log(typeof(score));

                    let valueInNumber = Number(score)
                    console.log(typeof valueInNumber);
                    console.log(valueInNumber);

Console Output:
string
string
number NaN
101

Conversion into Number

"33" => 33
"33abc" => NaN
true => 1; false => 0 

                        let a = null
                        console.log(Number(a))

Console Output: 0


Conversion into Boolean


                        let isLoggedIn = "hitesh"

                        let booleanIsLoggedIn = Boolean(isLoggedIn)
                         console.log(booleanIsLoggedIn);

Console Output:
true

"" => False
"Aakash" => True
0 => False
1 => True

Conversion into String


                        let someNumber = 33

                        let stringNumber = String(someNumber)
                        console.log(stringNumber);
                        console.log(typeof stringNumber);

Console Output:
true

33
String


JavaScript Arithmetic Operators

Arithmetic operators are used to perform arithmetic between variables and/or values.

Given that y = 5, the table below explains the arithmetic operators:

Operator Description Example Result
+ Addition x = y + 2 x = 7
- Subtraction x = y - 2 x = 3
* Multiplication x = y * 2 x = 10
/ Division x = y / 2 x = 2.5
% Modulus (division remainder) x = y % 2 x = 1
++ Increment x = ++y x = 6
-- Decrement x = --y x = 4

Assignment operators are used to assign values to JavaScript variables.

Given that x = 10 and y = 5, the table below explains the assignment operators:

Operator Example Same As Result
= x = y x = 5
+= x += y x = x + y x = 15
-= x -= y x = x - y x = 5
*= x *= y x = x * y x = 50
/= x /= y x = x / y x = 2
%= x %= y x = x % y x = 0

Some Operations


                    let value = 3
                    let negValue = -value
                    let numCheck = negValue + 5
                    console.log(numCheck);
                    console.log(negValue);

Console Output:
2
-3 


                    console.log("1" + 2);
                    console.log(1 + "2");
                    console.log("1" + 2 + 2);
                    console.log(1 + 2 + "2");

Console Output:
12
12
122
32 



                    console.log(+true);
                    console.log(+"");

Console Output:
1
0 



                    let gameCounter = 100
                    ++gameCounter;
                    console.log(gameCounter);

Console Output:
101


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