C Command Line Tutorial 6
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We’ve lined a complete of 5 C programming tutorials to date. Every tutorial targeted on one thing particular. In strategy of remaining near the subject, some generic ideas remained untouched. A few of these ideas we’ll be discussing right here on this tutorial. 

So let’s start.

You need to at all times correctly indent your code. For starters, indentation is a observe where-in you set areas/tabs/newlines to make the code look extra readable. Normally, traces of code related to a block or loop are positioned at similar hole. For instance, this is an unindented code:

#embody <stdio.h>

int fundamental (void)
{
int c =0, counter=0;
c = getchar();
whereas(c != EOF)
{
c = getchar();
if(c == 'n')
counter = counter+1;
}
printf("The input contains %d lines", counter+1);
return 0;
}

And this is the identical code with indentation utilized:

#embody <stdio.h>

int fundamental (void)
{
int c =0, counter=0;
c = getchar();

whereas(c != EOF)
{
c = getchar();

if(c == 'n')
counter = counter+1;
}

printf("The input contains %d lines", counter+1);

return 0;
}

So you’ll be able to see, the indented code appears to be like sorted out and straightforward to learn and overview.

You will have observed in earlier tutorials, we’ve got used the next strategy to increment a variable:

a = a+1;

Whereas there’s nothing unsuitable with this fashion, there’s one other manner which is common and used so much. It is to make use of an increment operator.

a++

Utilizing this fashion, the worth of ‘a’ increments by 1. Be aware that it is a post-increment. There is a pre-increment operator as nicely:

++a

The distinction between the 2 is in post-increment, the variable is first used after which its worth if increment. However, in pre-increment, the worth is first elevated after which the variable is used.

The next piece of code will higher clarify the distinction.

#embody <stdio.h>

int fundamental (void)
{
int a =0, b=0;

printf("a = %d", a++);
printf("n b = %d", ++b);

return 0;
}

The output of this program is:

a = 0
b = 1

So you’ll be able to see, whereas publish increment did not mirror instantly, pre-increment did. 

The identical logic applies to decrement operators as nicely.

#embody <stdio.h>

int fundamental (void)
{
int a =1, b=1;

printf("a = %d", a--);
printf("n b = %d", --b);

return 0;
}

The output is:

a = 1
b = 0

There are two methods in which you’ll remark code in C. One is utilizing ‘//’. This fashion, you’ll be able to solely remark a single line at a time.

// int a = 10;
// a = 9;

The opposite manner is to place /* …. */ across the traces. This lets you remark a number of traces without delay.

/* int a = 10;
a = 9; */

Up till now, we’ve got solely touched upon the whereas loop, whereby the code execution solely enters the whereas block if the situation is true.

whereas(situation)

{

/*

   line of code

   line of code

   ...

*/

}

There additionally exists a do-while loop, whereby the block of code is executed as soon as for the primary time after which the whereas situation is checked.

 do
{

// few traces of code

} whereas (situation);

Now, the query is when to make use of do-while? I am going to provide you with an instance. Suppose you need the person to enter a price which is larger than 10, and the requirement is to maintain asking the person to enter such a price till this system will get one. Then this is how the do-while loop will likely be useful in that case:

do
{
printf("Please enter a number greater than 10: ");
scanf("%d", &n);

}whereas(n<=10);

Subsequent up is ‘for’ loop, which like ‘whereas’ has a situation to test, but in addition has an increment assertion or decrement assertion that is useful in lots of circumstances.

for(initialization; situation; increment/decrement)
{
// traces of code right here
}  

Here is an instance code that prints all even numbers between Zero and 20.

#embody <stdio.h>

int fundamental()
{
int i;

for(i=0;i<=20;i=i+2)
printf(" %d ", i);

return 0;
}

In fact, there are various ideas and methods associated to ‘for’ loop, however we’ll focus on them slowly and steadily in our future tutorials. 

Right here, on this tutorial, we discovered some good ideas in addition to new ideas. We’ll be increasing upon these in tutorials to return. Till then, observe no matter we mentioned right here as we speak, and drop in a remark in case you have got any doubt or question.

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