05-Function, String

First, what is a function

* any C language Program is composed of one or more program segments (small programs), each of which has its own function, which we generally call " functions ".

* For example , in C language to write a MP3 player program, then its program structure as shown:

Second, the definition of function

1. steps to define a function

* function Name: What is the function name

* function Body: What does the function do and what code it contains

2. format

* Fixed format

return value type  function name (formal argument list) {    function Body}

* Example

SUM (intint  b) {    int c = a + b;}

Iii. parameters of the function

* The pass of a parameter is a value pass

* Parameter name cannot be the same as local variable within function

Four, function notice

* cannot nest defined functions

* dead Loop call, call yourself

* cannot be defined repeatedly and can be declared repeatedly

Five, function supplement

1. main function

* return value:0, normal exit,1, abnormal exit

2. printf functions

* #include

* return Value: Length of String

Vi.#include

1. The role of #include

It's purely a file copy.

Seven, array

1. features of the array

* only one type of data can be stored, such as an array of type int , an array of type float

* data stored inside is called " element "

2. Array Definitions

* declaring the type of an array

* Declare the number of elements in an array (how much storage space is required)

3. format

Element type array name [ number of elements ];

Like what:

int ages[3];

4. Initialize

int ages[5] = {35}; int ages[3] = {2}; int a[] = {n};

Eight, string

1. What is a string

* Simple string "ASI"

* one ' i ' is a character

2. Initialization of strings

3. commonly used string processing functions

* strlen(note Chinese)  

05-Function, String