一文搞懂：_itoa_itow_itotatoiatofatol

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函数原型：

char _itoa( int value, char string, int radix ); //ANSI

wchar_t _itow( int value, wchar_t string, int radix );//UNICODE

_itot 只是一个宏，根据系统定义的字符集来去_itoa或者_itow， 对应的安全函数为_itot_s

说明:把int 转化为字符串,value为被转化的值,string为转化的目的字符串, radix为基数必须在2到36之间.

所需头文件 #include

举例说明:这里用它们的安全函数: _itoa_s _itow_s

char szYearA【5】 = {0};

WCHAR szYearW【5】 = {0};

_itoa_s(100, szYearA, 10);

_itow_s(100, szYearW, 10);

atoi atof atol

Convert strings to double (atof), integer (atoi, _atoi64), or long (atol).

double atof( const char *string );

int atoi( const char *string );

_int64 _atoi64( const char *string );

long atol( const char *string );

举例：

double d1 = atof(""sa34""); //代码效果参考：https://v.youku.com/v_show/id_XNjQwMDQwMjMxNg==.html

double d2 = atof(""34gdf""); //d2 = 34.000000000000000

double d3 = atof(""-0343""); //d3 = -343.00000000000000

double //代码效果参考：https://v.youku.com/v_show/id_XNjQwNjg1NDM2OA==.html

int i1 = atoi(""df""); //i1 = 0

int i2 = atoi(""54.34""); //i2 = 54

int i3 = atoi(""-54""); //i3 = -54

int i4 = atoi(""09""); //i4 = 9