Difference between using brackets in for loop C# and not using it

Question

The output of the following code is different from the ouput from the second code can someone explain the problem?

Code 1:

for(int i = 1; i <= intInput; i++)
{
    for(int j = 1; j<=i; j++)
    {
        Console.Write('+');
        Console.WriteLine();
    }                         
}
if intInput is 4 Ouput is:
+
+
+ 
+

Code 2:

for(int i = 1; i <= intInput; i++)
{
    for(int j = 1; j<=i; j++)
        Console.Write('+');
        Console.WriteLine();                                    
}
if intInput is 4 Ouput is:

+
++
+++
++++

I know how this line of codes works but i dont understand what difference the brackets make on both codes?

If you don't specify curly braces it will consider first statement immediate to the for statement as inside the for loop to be repeatable. — Jenish Rabadiya, Nov 06 '15 at 10:31
looks like some kind of homework. Why you don't use the debugger to find out yourself? — Dom84, Nov 06 '15 at 10:34
Or you are a Python programmer. :) In Visual Studio, I always always use ctrl+k, ctrl+d to format the document, and then you also see nested if/for/class/whatever code a lot better. — Andreas Reiff, Nov 06 '15 at 10:53

score 5 · Accepted Answer · edited May 23 '17 at 12:30

When you write;

for(int j = 1; j <= i; j++)
{
    Console.Write('+');
    Console.WriteLine();
}

Both Console line works until j loops out.

But when you write

for(int j = 1; j <= i; j++)
    Console.Write('+');
    Console.WriteLine();

Only first Console works until j loops out. That's why second one is equal to;

for(int j = 1; j<=i; j++)
{
   Console.Write('+');
}
Console.WriteLine();

If there is one statement included in the loop, the curly brackes can be omitted. But using them is always a better approach.

Read: Why is it considered a bad practice to omit curly braces?

score 4 · Answer 2 · answered Nov 06 '15 at 10:32

4

You second case effectively means:

    for(int i = 1; i <= intInput; i++)
    {
        for(int j = 1; j<=i; j++)
        {
            Console.Write('+');
        }
        Console.WriteLine();                                    
    }

Indentation means nothing for compiler it is only for you

answered Nov 06 '15 at 10:32

ISanych

21,590
4
32
52

you used Python to much! – kame Nov 06 '15 at 10:38
@kame Yeb bro Its true:) – moji Nov 06 '15 at 10:42

score 2 · Answer 3 · answered Nov 06 '15 at 10:30

The loop has a scope. If you do not include the braces, only the first line is in the loop. If you have the braces, everything inside falls under the scope of the loop.

In this case, the first example write a "+" to the console as well as a new line every iteration of the inner loop.

The second case, the inner loop only executes the "+" writing on each inner iteration. The outer loop adds the new line.

score 0 · Answer 4 · answered May 02 '20 at 20:21

0

If alter 1 with i in second loop then it will work same

for (int j = **i**; j <= i; j++)
   Console.Write('+');
   Console.WriteLine();

answered May 02 '20 at 20:21

Fuad Teymurov

73
1
10

Difference between using brackets in for loop C# and not using it

4 Answers4

Linked

Related