Correcting format (#26885)

This commit is contained in:
DEBSUBHRA ROY
2018-12-18 23:08:44 +05:30
committed by Christopher McCormack
parent 6816c92620
commit df2d3de61e

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@ -22,7 +22,7 @@ Now that you have that background, let's start with our 'Hello, World' program.
## Hello world in C
```C
#include <stdio.h>
#include <stdio.h> <!-- stdio or standard input output is a dirctory file in C-->
int main(void)
{
@ -46,11 +46,9 @@ int main(void)
```
This code declares the main function. The main function is special- it will always get called and is always the 'main' part of your program. If this isn't in your program, your program can't run and won't compile.
Starting the function declaration with `int` means that this function will give an `int` value when it's done running through its code- it's this function's output. `int` is the 'integer' data type, and integers are whole numbers like -3, 0, or 18. So we know that this code will run, and when it's done, it will give us back an integer. By convention, this integer is 0.
Starting the function declaration with `int` means that this function will give an `int` or integer value when it compiles the code- it's this function's output. `int` is the 'integer' data type, and integers are whole numbers like -3, 0, or 18. So we know that this code will run, and when it's done, it will give us back an integer. By convention, the integer has a `garbage value`.
Next is `main`. `main` is the name of this function, and as you learned earlier, it's important to have a `main` function because your program won't work without it. `main` is followed by `(void)`. This tells the compiler that this function doesn't take any parameters, meaning that it has no input.
This might not make a lot of sense right now, but you'll be learning more about this when you start reading about functions in C later. For now, just remember that `main` is required for your C program, it isn't taking any input, and it's giving a number as its output.
Next is `main`. The `main` function is the function which acts the parent where all the other elements and functions are it's children. The `main` is followed by `(void)`. This tells the compiler that this function doesn't take any parameters, meaning that it has no input.
Finally, there are the brackets: `{` and `}`. These mark the beginning and end of the function. The open curly bracket (`{`) marks the beginning, and the close curly bracket (`}`) marks the end. Everything between the two is within the function.
@ -60,7 +58,7 @@ Now let's look at the meat of the program:
printf("Hello, World!\n");
```
`printf` is a function that takes text and prints it to the screen. The parenthesis indicates what information we want the `printf` function to take and print to the screen. We show that this is a string we want printed by surrounding it in quotes "like this".
`printf` is a function that takes input and prints it to the screen. The parenthesis indicates what information we want the `printf` function to take and print to the screen. We show that this is a string we want printed by surrounding it in quotes "like this".
Notice the \n found within the quotes- this tells the `printf` function to print a newline. A newline is what gets printed when you hit enter on your keyboard. Without explicitly telling C to print a newline, everything will be printed on the same line.
@ -112,15 +110,21 @@ Make a new program with `file` -> `new` -> `Source File`, then copy over the hel
# Before you go on...
## A review
* C is lingua franca of programming languages.
* C was used to re-implement the Unix operating system.
* C is useful because it's small, fast, and has access to low-level operations. Because of this, it gets used a lot in robotics, operating systems, and consumer electronics, but not in things like webpages.
* A C program has a few critical parts:
* The include statement, which tells the C compiler where to find additional code that will be used in the program.
* The main function, which is where the code will first be executed and is required in order to compile.
* Stuff within that main function which will get executed, including a return statement that closes the program and gives a value to the program that called it.
* C needs to be compiled in order to run.
* C can be used to access specific hardware addresses and to perform type punning to match externally imposed interface requirements, with a low run-time demand on system resources.
<ul>
<li>C is lingua franca of programming languages.</li>
<li>C was used to re-implement the Unix operating system.</li>
<li>C is useful because it's small, fast, and has access to low-level operations. Because of this, it gets used a lot in robotics, operating systems, and consumer electronics, but not in things like webpages.</li>
</ul>
#### A C program has a few critical parts:
<ul>
<li>The include statement, which tells the C compiler where to find additional code that will be used in the program.</li>
<li>The main function, which is where the code will first be executed and is required in order to compile.</li>
<li>Stuff within that main function which will get executed, including a return statement that closes the program and gives a value to the program that called it.</li>
<li>C needs to be compiled in order to run.</li>
<li>C can be used to access specific hardware addresses and to perform type punning to match externally imposed interface requirements, with a low run-time demand on system resources.</li>
</ul>
#### More information:
* [C Programming Tutorials.](https://www.tutorialspoint.com/cprogramming/)