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What is a good way to get better at For Loops (C++/Java)

KING OF THE DIRTY DANS

Hello Friends.

 

I will admit, I suck ass at doing For Loops.

What kinda programs are good exercises for gaining for loop skills

 

 

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Strip a for loop down to bare minimum:

for (initialization; condition; action) {
  // stuff
}

It's purpose is not meant to be just be a "have an int and increment it" as an index. It can be used for many more things than just that. Consider this for iterating over a linked list:

Item *head;
for (Item *item = head; item != null; item = item.Next()) {
  // do things with item
}

Or this for iterating over a ring:

Item *head;
for (Item *item = head; item != head; item = item.Next()) {
  // do things with item
}

Or this for reading a file until End Of File is hit:

byte[] data; // you'd need to allocate first of course
for (Result res = file.Read(data); res != EOF; res = file.Read(data)) {
  // do things with data
}
Spoiler

Feel free to adapt this, but note that this is from memory.

Pseudocode for imagining what a for loop does (just in a more attractive notation):

/* This */
for (int i = 0; i < some_num; i++) {
  // stuff
}

/* Is this underneath */
	int i = 0; // initialization
Loop:
	// stuff
	if i < some_num: // condition
		i++; // action
		jump Loop;
	else
		jump EndLoop:
EndLoop:
	// continue on

This will always be the same, for the linked list or the file reading example. A for loop is merely that construct. Once you get that, you should be more comfortable with it.

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Devblox has good advice, and depending what you're working on (and what language and version), I'd also consider using lambdas:

 

List<String> strList = getTheListOfStrings();
strList.foreach(str -> { 
    printTheString(str);
});

// can also be abbreviated to

strList.foreach(str -> this::printTheString);

 

Javascript has got the same sort of thing in it.

 

For brain-melting advanced programmer points, consider using Streams.

 

 

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Also if you are removing things from the thing you are iterating on, remember to use a concurrency-compatible operation.

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