JAVASCRIPT CL - 8

DAY -8

HOW TO CHANGE THE WHILE LOOP TO FOR LOOP FOR UNDERSTANDING

SAMPLE WHILE LOOPING CODE:

let i=1;
        while(i<=5){
            console.log(i);
            i++

        }// OUTPUT 1 2 3 4 5

SAMPLE FOR LOOPING CODE:

for(j=0;j<=5;j++){
            console.log(j);

        } //OUTPUT : 0 1 2 3 4 5

NEXT WILL DICUSS
1.ARROW FUNCTION
2.ARRAY
3.FOREACH

ARROR FUNCTION:

NORMAL FUNCTION CODE :
syntax for function

function functionname( variable){
        log.();
    }
    functionname(value)

NOW , WE CHANGE THE FUNCTION TO ARROW FUNCTION

syntax for arrow function

()=>{ 
        log.("hi"); 
       }

IN ARROW FUNCTION WILL WRITE THE ONE LINE CODE curly braces IS NOR MANITAOR

SAMPLE CODE :

()=> log.("HI");

1.WHY WILL USE NARROW FUNCTION ?
* NORROW FUNCTION ONLY USED TO SMILIFY THE FUNCTION ONLY.
2.THEN WHY CALL ARROW FUNCTION ?
* CREAT ONE VARIABLE TO CALL THE ARROW FUNTION
Syntax:

const variableName = () => console.log("HI");

sample code

//arrow function
        const display = () => console.log("hi");
        display() //  OUTPUT : hi

DIFFERENT BETWEEN HOISTED AND NON- HOISTED
* FUNCTION IS CALLED HOISTED .BECAUSE BEFORE DECLARECTION WILL USES THE FUNCTION NAME IS CALL HOISTED
* VARIABLES IS CALLED A NON-HOISTED .BECAUSE BEFORE DECLARECTION IS NOT WORKING .BECAUSE IF DECLARE THE VARIABLE NAME THEN ONLY THE MEMORY WILL CREATE SO VARIABLE IS CALLED NON-HOISED
EXAMPLE CODE FOR NON-HOISTED

display() // VARIABLE
    const display = () => console.log("hi"); // IF WE CALLED THE VARIABLE BEFORE MENCTION IS ACCORED ERROW 

ARRAY:

• SET OF DATA STORED IN A SINGLE VARIABLE AND THE DATA WILL STORE IN A INDEX FORM . AND ARRAY WILL 0TH INDEX WHY WE WILL YOU ARRAY ?
• IN REAVLE WAORD WE STORE THE ONE STUDENT EXAM MARKS TAM = 87 ENG = 77 MATH = 89 SCI = 98 SS = 88
• IN THIS SUTIVATION WE WILL CERATE A MULTIPLE VARIABLES . SO SOVE THIS ISSUE TO WE USE THE ARRAY . SO USING ARRAY SET OF PERTICULR DATA IN A STORED IN A SINGLE VARIIABLE

EXMPLE:
MARKS = [ 87 77 89 98 88] // THIS IS CALLED ARRAY

IN JAVASCRIPT WILL WRITE THIS CODE

const marks = [ 87 77 89 98 88] // 

SAMPLE CODE :

const marks = [2,3,4,5,6];
        console.log(marks[3]);// OUTPUT : 5
        console.log(marks);//Array(5) [ 2, 3, 4, 5, 6 ]
        console.log(marks);// OUTPUT : Array(5) [ 2, 3, 4, 5, 6 ]
        // reassin the value of index 3 
        marks [3]= 45;// reassin the value 
        console.log(marks);// outpur : Array(5) [ 2, 3, 4, 45, 6 ]