C# Display a pyramid

Question

Hi!

I have found this code in the internet:

for (int i = 1; i< 10; i++)

{

for(int j= 1; j<= i; j++)

{

Console.Write(i);

}

Console.WriteLine();

}

Console.ReadKey();

This code is used to display a pyramid like this:

1

22

333

4444

55555

666666

7777777

88888888

999999999

But I do not understand the code? Can someone please simplify and explain what it means?

Thankful for your help!

Answer 1

Hi Maya,

I will do my best to explain line-by-line. I hope you find this helpful.

/*

This here is the beginning of a for-loop wherein i starts at 1

and continues up to, but not including, 10.

*/

for (int i = 1; i< 10; i++)

{

/*

This here is the beginning of a for-loop wherein j starts at 1

and continues up to and including, i. So, when i = 1,

j will equal 1, then stop. When i = 5, j will equal 1, then 2,

then 3, then 4, then 5, but stop when j = 6.

*/

for(int j= 1; j<= i; j++)

{

/*

This line will execute for every j. So, if i = 5, j will be

1, 2, 3, 4, 5. As such, this line will print 5 i's. But since

it is "Console.Write(i);" and not "Console.WriteLine(i);",

it will put every number on the same line.

*/

Console.Write(i);

}

/*

Once the inner for-loop finishes, we want the next set of numbers to

appear on the next line. So, by putting a "Console.WriteLine();" with

nothing in it, it simply moves us down to the next line.

*/

Console.WriteLine();

}

/*

Once both for-loops finish, this will just wait for the user to press any key.

*/

Console.ReadKey();