Iterative Control

 While loop

// While Loop

let x = 5;

while (x) {

    console.log(x);

    x --;

}

// do while Loop

let y = 10;

do {

   

    console.log(y);

    y--;

} while (y);

for Loop

array = [1,2,3,4,5]

for (let index = 0; index < array.length; index++) {

    if (array[index] %2 == 0)

    {

        const element = array[index];

    console.log(element);

    }

       

}

for in loop 

This loop is used to access elements of an object. 

//  for in loop

person = {

    name: 'hari',

    age:'25'

};

for (const key in person) {

     

    console.log(key,person[key]);

}

Similarly, we can iterate object such as array. In case of array key is 0,1,2... and value can be accessed as below.

//  for in loop

arr = [10,20,30,40,50]

for (const key in arr) {

     

    console.log(key,arr[key]);

}

Output 

0 10

1 20

2 30

3 40

4 50

for of loop 

This loop works similar to for loop in Python and foreach loop in Java

cars = ["Tesla",4,6,"Mercedes"]

for (const car of cars) {

    console.log(car)

}

Transfer statements 

break,continue,return - Same as C language

break - it is used in body of loop or switch

continue - bypass current execution

return - to return value via function