CODEWITHSUNDEEP
javaloopsfor-loopiteration
DianaZ
DianaZ

Reputation: 41

Java For Loop to iterate 100 64 36 16 4 0 4 16 36 64 100 using a single variable

I want to write a for loop in the format below, using only a single variable e. The (____) blank spaces are the only things I want changed. It should print out 100 64 36 16 4 0 4 16 36 64 100. I'm not sure how get it to reiterate after it reaches 0.:

for(_____________________)

    System.out.print(______________ + " ");

System.out.println();

This is what I tried so far. Is there a way to use only one variable e and still get it to reiterate through numbers it already used?:

for(int e = 10; e > 0; e -= 2)

    System.out.print(e * e + " ");

System.out.println();

Upvotes: 3

Views: 835

Answers (4)

Linora
Linora

Reputation: 10988

To take advantage of the fact that negative number multiplied to a negative number gives a positive number we can use your current solution. So as an example: e = 2 gives you 4 and e = -2 also gives you 4. Thus we can make a minor adjustment to your function:

for(e = 10; e >= -10; e -= 2)

    System.out.print(e * e + " ");

System.out.println();

That should give 100 64 36 16 8 4 0 4 8 16 36 64 100.

Upvotes: 1

that other guy
that other guy

Reputation: 123480

The competent programmer is fully aware of the strictly limited size of his own skull; therefore he approaches the programming task in full humility, and among other things he avoids clever tricks like the plague.

-- Edsger W. Dijkstra

    for(int e : new int[]{ 100, 64, 36, 16, 4, 0, 4, 16, 36, 64, 100 }) {
        System.out.print(e + " ");
    }
    System.out.println();

Upvotes: -1

thegrinner
thegrinner

Reputation: 12243

Use the fact the negative numbers multiplied by each other are positive and use e >= -10.

    for (int e = 10; e > -11; e -= 2)
        System.out.print(e * e + " ");
    System.out.println();

I find it more readable to go negative to positive though. And it's generally a good idea to add the brackets in:

for (int e = -10; e < 11; e += 2) {
    System.out.print (e * e + " ");
}
System.out.println();

Upvotes: 3

rgettman
rgettman

Reputation: 178263

Use the fact that e2 = (-e)2, and stop when e is no longer greater than or equal to -10.

Upvotes: 10

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