# C轉換說明符和修飾符

## 方便的C轉換說明符和修飾符參考

`%d`/`%i` 有符號十進制整數
`%u` 無符號十進制整數
`%c` 無符號`char`
`%s` 細繩
`%p` 十六進制形式的指針
`%o` 無符號八進制整數
`%x`/`%X` 無符號十六進制數
`%e` 指數格式中的浮點數`e`符號
`%E` 指數格式中的浮點數`E`符號
`%f` `double`十進制格式的數字
`%g`/`%G` `double`十進制格式或指數格式的數字（取決於值）

``````printf("%4d\n", 1);
printf("%4d\n", 12);
printf("%4d\n", 123);
printf("%4d\n", 1234);``````

``````   1
12
123
1234If you put a dot before the digit, you are not telling the precision: the number of decimal digits. This of course applies to decimal numbers. Example:
printf("%4.2f\n", 1.0);
printf("%4.3e\n", 12.232432442);
printf("%4.1e\n", 12.232432442);
printf("%4.1f\n", 123.22);
will print:
1.00
1.223e+01
1.2e+01
123.2In addition to digits, we have 3 special letters: h, l and L.

h, used with integer numbers, indicates a short int (for example %hd) or a short unsigned int (for example %hu)
l, used with integer numbers, indicates a long int (for example %ld) or a long unsigned int (for example %lu).
L, used with floating point numbers, indicates a long double, for example %Lf

More clang tutorials:

Introduction to the C Programming Language

C Variables and types

C Constants

C Operators

C Conditionals

How to work with loops in C

Introduction to C Arrays

How to determine the length of an array in C

Introduction to C Strings

How to find the length of a string in C

Introduction to C Pointers

Looping through an array with C

Booleans in C

Introduction to C Functions

How to use NULL in C

Basic I/O concepts in C

Double quotes vs single quotes in C

How to return a string from a C function

How to solve the implicitly declaring library function warning in C

How to check a character value in C

How to print the percentage character using `printf()` in C

C conversion specifiers and modifiers

How to access the command line parameters in C

Scope of variables in C

Can you nest functions in C?

Static variables in C

C Global Variables

The typedef keyword in C

C Enumerated Types

C Structures