Having trouble using for-each loops. JAVA

[CreepyPro]

I'm trying to loop through an Array of ints(using a for-each loop) and checking if there's a number bigger than 0 at that index but I'm getting ArrayIndexOutOfBounds: 5 almost every time.

But if I use a normal for loop the method works fine.

 

	public boolean hallIsClear() {
		int c=0;
		/*
		for(int toys : hall) 
			c += hall[toys];
		*/
		
		for(int i=0;i<hall.length;i++)
			c += hall[i];
		return c == 0;
	}

 

[minibois]

The way you are using 'toys' in the for-each loop is what is going wrong.

You are trying to use the for-each like it is a for-loop, while you can actually work with it quite a bit easier.

 

As GeeksForGeeks says:

for (type var : array) 
{ 
    statements using var;
}

https://www.geeksforgeeks.org/for-each-loop-in-java/

 

In your example, you can basically do this:

for(int toys : hall) 
	c += toys;

What the first line accomplishes:

"For each integer value in hall, that I will now call 'toys', do this:"

What the second line does: 
"Take value 'c' and add the current value I am checking (toys) to this variable".

 

What is probably happening in your first example, is that one of the values of 'toys' (so the value of one of the variables in the array) is larger than the (length-1) of your array. Causing the out-of-bound error.

[CreepyPro]

4 minutes ago, minibois said:

The way you are using 'toys' in the for-each loop is what is going wrong.

You are trying to use the for-each like it is a for-loop, while you can actually work with it quite a bit easier.

 

As GeeksForGeeks says:

for (type var : array) 
{ 
    statements using var;
}

https://www.geeksforgeeks.org/for-each-loop-in-java/

 

In your example, you can basically do this:

for(int toys : hall) 
	c += toys;

What the first line accomplishes:

"For each integer value in hall, that I will now call 'toys', do this:"

What the second line does: 
"Take value 'c' and add the current value I am checking (toys) to this variable".

 

What is probably happening in your first example, is that one of the values of 'toys' (so the value of one of the variables in the array) is larger than the (length-1) of your array. Causing the out-of-bound error.

Thanks for the explanation, everything works as it should now. 

Have a nice day