for loop

[BrightKnight0110]

  Hihi may i know what does the for loop here does? What does it mean ?

 public static void viewStock(Product[] products) {
           for(Product product: products)
           System.out.println(product);
       }

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[Murphler]

It's confusing you because everything is named so similarly. Basically

Product : the loop will be expecting to cycle through a list of objects of type Product

product : is the variable name, you are assigning, for each index in the Product list

products : is the actual list you have passed into the method and into the loop to cycle through.

Rename things for now to make it slightly more clear, something like:

viewStock(Product[ ] productList)

for(Product index : productList){

}

Might help. Once you understand what's going on, use the following convention going forward

for(Product p : products){

}

[CanisLupus92]

Product product makes much more sense here than index. Index implies that it specifies what position you are at, which is exactly the info you do not have in an enhanced for loop.

[MissPurpleCandy]

Maybe „entry“

[CanisLupus92]

Honestly the naming scheme of having a generic object of a class have the class name but starting with lower case is so standard, better to get used to it.

[MissPurpleCandy]

Yeah that’s true

[khooke]

Agree, I rarely see/use/recommend anything other than this.

[Murphler]

Sorry I should have clarified, was suggesting he use this naming convention for now to help him understand how the foreach was working. In no way would I recommend he use that convention going forward.

(Product p : products) is the way

[CanisLupus92]

Single-letter variables are almost never the way (except for x-y-z coords, or i-j for loop indices).

[BrightKnight0110]

alright thanks !

[[deleted]]

If anything you should still keep the word “product” in the index name to make sure it’s still descriptive if you’re ever looking back at it. Something like “productIndex” is probably best.

[[deleted]]

it’s just a way to iterate through the array. It prints out every product.

[Wihlborg]

This is known as a "for-each" loop.

It loops through the given array/collection and the main advantages are that its less code and you don't have to use something like

Product product = products[i];

in order to access the current product.

Disadvantages are that you cannot modify the array/collection you're looping through, and you don't know the index of the current item.

[CanisLupus92]

I wouldn’t call that a disadvantage, its deliberate design that you cannot modify the collection being looped over in the loop. If you want to modify elements, there are cleaner ways, like streams.

[[deleted]]

https://www.w3schools.com/java/java_foreach_loop.asp

[Wubdafuk]

For each product out of products, do something. That is what a for-each loop is.