2.6 KiB
2.6 KiB
Compilation Steps
- Preprocessing: The preprocessor obeys commands that begin with #, also known as directives Commands for the preprocessor are called directives. Directives begin with a pound sign, and they do not end with a semicolon.
Example:
#include <stdio.h>
- Compiling. A compiler translates then translates the program into machine instructions.
- Linking: The generated objects are combined to create a complete executable.
The preprocessor is typically integrated with the compiler.
Types
Strings
A string literal is characters enclosed in double quotation marks.
A newline can be inserted using \n.
Integers
An integer is a way to store a whole number. In C, integers are signed by default.
Floats
A float is a decimal value. Slower arithmetic and inexact values are both drawbacks of using floats.
Variables
A variable must be declared before it is assigned.
Formatting specifiers
Standard library
Formatting specifiers
| Specifier | Function |
|---|---|
%d |
Decimal representation: Display a value as a base 10 (hence the decimal) integer. |
%f |
Fixed point decimal representation. Specify the number of places to round to by adding a decimal and a number, eg %.2f would round to two decimal places. |
%e |
|
| For number formatting specifiers, the convention is as follows: | |
%-a.bX |
|
%: Start of the formatting specifier |
|
-: (optional) If included, justify value left in space. Otherwise, justify right in space |
|
a: (optional) If included, the size of the field in characters. |
|
.: Separator between a and b. Optional if b is not specified |
|
b: The number of decimal places to round to |
|
X: The type of format to use, and the end of the specifier. Use d for integer base 10 (decimal) representation, f for fixed point decimal, and e for exponential notation, and g to select between fixed point and exponential, whichever is shorter. |
printf
Write a string to standard output. f indicates that it's a formatting string. The string will not include move the cursor to a newline, append \n to the end of the string to do so.