C (programming language) facts for kids

The C programming language is a powerful way to give instructions to a computer. It was created in the early 1970s by Dennis Ritchie and Ken Thompson at Bell Labs. C was first used to build the operating system called UNIX. It lets programmers write step-by-step instructions for computers.

C programs are "compiled." This means they are turned into a special code the computer understands directly. This special code is called machine code. Programs made with machine code run very fast. This makes C great for building operating systems. Many operating systems, like Linux and UNIX, use C.

C has only a few main commands. Most tasks are done using "libraries." These are collections of ready-made code that programmers can reuse.

C works on many different types of computers. This is why it's called a "portable" language. A program written in C can often be used on many different computer systems. The way C is written has also influenced many other languages. These include C++, C#, and Java.

What is a Programming Language?

A programming language is like a special language that humans use to talk to computers. It lets us write instructions for the computer to follow. These instructions are called a "program."

How C Programs Work

When you write a program in C, you create a text file. This file contains all your instructions. Then, a special program called a "compiler" reads your C code. The compiler translates your code into machine code. Machine code is the basic language that a computer's processor understands.

Because C programs are turned directly into machine code, they run very quickly. This is why C is often used for important software. It is used for things like operating systems and game engines.

Why C is Popular

C is popular for several reasons:

• Speed: C programs run very fast because they are close to the computer's hardware.
• Flexibility: You can use C to write many different types of programs. This includes operating systems, games, and apps.
• Portability: C programs can often be moved and run on different computer systems.
• Influence: Many modern programming languages use ideas from C. Learning C can help you understand other languages.

Example Code

Here is a simple example of a program written in C. When you run this program, it will display "Hello world!" on your computer screen.

#include <stdio.h>

int main() {
    printf("Hello world!\n");
    return 0;
}

Let's look at what each part of this code does:

• #include <stdio.h> tells the program to get ready to use standard input and output tools. This allows the program to show text on the screen.
• int main() is called the main function. This is where the computer starts running the code in a C program.
• printf("Hello world!\n"); is the command that displays text. In this case, it shows "Hello world!" The `\n` part means "start a new line" after the text.
• return 0; tells the computer that the program has finished running. It also signals that everything worked correctly.

Related Pages

• C dynamic memory allocation
• C++
• C Sharp (programming language)
• Objective-C

Images for kids

• 

  Dennis Ritchie (right), the inventor of the C programming language, with Ken Thompson

• 

  "Hello, World!" program by Brian Kernighan (1978)

• 

  The C Programming Language

• 

  The TIOBE index graph, showing a comparison of the popularity of various programming languages

See also

In Spanish: C (lenguaje de programación) para niños