what is enhanced for loop and how it works?

Question

for(i: arr[])

Answer 1

Different languages implement enhanced for loops in different ways. But the common objective is to transverse through all of the elements in an array, list or any other collection.

Out of the languages you asked I can tell you about java and js

In java you can use enhanced loop on arrays and classes implementing the Collections framework.

Example usages are

//for arrays
for (var e : Object[] {54, 5, 4, 535, 6}){
//you can replace var with the datatype of the array
}

//for Collections (We'll use an List here)
for (var e : Arrays.asList(4,3,5,4,3,5,3)) {
}

**"How they works?" continues below ☺

Answer 2

"How they work?"

I ll give you examples in java

Look at the following code. Basically it declares an array an prints all the values of it.

var arr = new int[] {54,5,3,6,6,3,2,81};

for (var i = 0; i < arr.length; i++) {
System.out.println(arr[i]); //prints all the integers in arr
}

You can simply convert this code into this

for (var i : arr) {
System.out.println(i); //prints all the integers in arr
}

Clean right? 😜 This also reduce verbosity and saves the time

For js also we have a similar thing like this. They are for ..in loops and for .. of loops.

I ll mention you lessons for that
https://www.sololearn.com/learn/JavaScript/2970/?ref=app

Answer 3

It will index a variable through an array and run the loop content for each element in the array.

int[] arr = {5, 3, 8, 6, 0};

for (int el: arr) {
//...
}
//corresponds:
for (int i = 0; i < arr.length; ++i) {
int el = arr[i];
//...
}

keyword
\ _____/
|
| datatype of each
| item of the array.
| \ ______________/
| |
| | variable name
| | whose value will be
| | changed in each
| | iteration of the loop.
l | \ _________________/
| | |
| | | The array that
| | | is being
| | | iterated through.
| | | \ ______________/
| | | |
| | | | Basic code
| | | | that will be ran
| | | | for each item
| | | | in the array.
| | | | \ ___________/
v v v v v
for (int el: arr) {...}

Answer 4

it is like normal for() loop, but instead i++ and using e=array[i],
you by simple way direct get element from array into variable e
and then you can work with it like s.println(e)

but e is copy of value, so e++ change nothing in array (or collection)

Answer 5

Nice!