Question about Java programming...

[Ty44ler]

How would I convert this 'for' loop into a 'while' loop?

int sum=0;
for (int i=0; i<100; i++)

{
sum+=i;
}



Also, how would I convert it into a do-while loop?

[jkrohn]

Why would you want to? You're going to have to manually keep track of the i in either a while or a do-while loop.

Jkrohn

[Ty44ler]

Actually I think I figured it out... do these look correct?

While loop:
int sum=0;
int i=0;
while (i<100){
sum+=i++;
}


Do-While:
int sum=0;
int i=0;
do{
sum+=i++;
}
while(i<100);

[xelnanga]

Originally Posted by jkrohn

Why would you want to? You're going to have to manually keep track of the i in either a while or a do-while loop.

Jkrohn

This exactly. Unless you were instructed to change it by someone, I think for loop would work best here.

As for your code, look here:

While loop: //make While lower case
int sum=0;
int i=0;
while (i<100){
sum+=i++;
}


Do-While: //make this a comment
int sum=0;
int i=0;
do{
sum+=i++;
}
while(i<100);

and btw, your code is just longer and not as efficient as a single for loop. This is exactly why loops are used. By the way, where's the end of your for loop? You want to i++ and then what else do you want to run with it? Or did you just forget a semi-colon?

[jkrohn]

Originally Posted by Ty44ler

Actually I think I figured it out... do these look correct?

While loop:
int sum=0;
int i=0;
while (i<100){
sum+=i++;
}


Do-While:
int sum=0;
int i=0;
do{
sum+=i++;
}
while(i<100);

Those are quite wrong unfortunately.

How the for loop works.
1) Checks to see if I meets the condition
2) Adds I to sum
3) Increments I, back to 1

How your while loop works.
1) Checks to see if I meets condition
2) Increments I
3) Adds I to sum, back to 1

How your do-while works.
1) Increment I
2) Add I to sum
3) Check to see if I meets condition, back to 1

Also as you can see from above, the while checks *before* incrementing while the do-while checks *after* incrementing. As a result the while will not process I = 100 whereas the do-while will. Also the endpoints for these are off due to the incrementing of I before the addition.

I have a feeling this is schoolwork, no?

[Rootstonian]

Yeah, CS 101, "Program Flows"

Sequential Statements
If Else Statements
For Loops
While Loops
Do While Loops

As JK mentions, a Do While loop will process it's contents AT LEAST once.