个人参考http://blog.youkuaiyun.com/v_july_v/article/details/9024123写的字符串转整数函数。思路还是一样的,欢迎大家点评。
#include <stdlib.h>
#include <stdio.h>bool isspace(int x)
{
if(x=='\b'||x=='\t'||x=='\r'||x=='\f'||x=='\n'||x==' ')
return true;
else
return false;
}
bool isdigit(int x)
{
if(x>='0'&&x<='9')
return true;
else
return false;
}
int StrToInt(const char *str)
{
//------系统常量-------
static const int MAX=INT_MAX/10;
static const int MAX_R=INT_MAX%10;
int num=0;
bool minus=false;
bool overflow=false;
//1.检测是否为空指针
if(str!=NULL)
{
printf("非空字符串\n");
const char *digit=str;
//2.检测字符串前存在空格则继续检测
while(isspace((int)*digit))digit++;
//3.正负号检测
if(*digit=='+')
digit++;
else if(*digit=='-')
{
digit++;
minus=true;
}
while(*digit!='\0')
{
//4.数字字符判断
if(*digit>='0'&&*digit<='9')
{
//5.溢出判断
if(num>MAX||(num==MAX&&(*digit -'0')>7))
{
//num=INT_MAX;
overflow=true;
break;
}
num=num*10+(*digit -'0');
digit++;
}
else
{
break;
}
}
}
else
{
printf("空字符串");
}
//6.修正结果为正数还是负数
if(overflow==true)
return minus==true? INT_MIN:INT_MAX;
else
return minus==true? -num:num;
}
int main(void)
{
int m,n;
char *str = "123456789.67";
char *str_t="2147483648";//NULL;
m = StrToInt(str_t);
n = atoi(str);
printf("int=%d,%d\n",n,m);
while(1);
return 0;
}#include <stdlib.h>
#include <stdio.h>
bool isspace(int x)
{
if(x=='\b'||x=='\t'||x=='\r'||x=='\f'||x=='\n'||x==' ')
return true;
else
return false;
}
bool isdigit(int x)
{
if(x>='0'&&x<='9')
return true;
else
return false;
}
int StrToInt(const char *str)
{
//------系统常量-------
static const int MAX=INT_MAX/10;
static const int MAX_R=INT_MAX%10;
int num=0;
bool minus=false;
bool overflow=false;
//1.检测是否为空指针
if(str!=NULL)
{
printf("非空字符串\n");
const char *digit=str;
//2.检测字符串前存在空格则继续检测
while(isspace((int)*digit))digit++;
//3.正负号检测
if(*digit=='+')
digit++;
else if(*digit=='-')
{
digit++;
minus=true;
}
while(*digit!='\0')
{
//4.数字字符判断
if(*digit>='0'&&*digit<='9')
{
//5.溢出判断
if(num>MAX||(num==MAX&&(*digit -'0')>7))
{
//num=INT_MAX;
overflow=true;
break;
}
num=num*10+(*digit -'0');
digit++;
}
else
{
break;
}
}
}
else
{
printf("空字符串");
}
//6.修正结果为正数还是负数
if(overflow==true)
return minus==true? INT_MIN:INT_MAX;
else
return minus==true? -num:num;
}
int main(void)
{
int m,n;
char *str = "123456789.67";
char *str_t="2147483648";//NULL;
m = StrToInt(str_t);
n = atoi(str);
printf("int=%d,%d\n",n,m);
while(1);
return 0;
}#include <stdlib.h>
#include <stdio.h>
bool isspace(int x)
{
if(x=='\b'||x=='\t'||x=='\r'||x=='\f'||x=='\n'||x==' ')
return true;
else
return false;
}
bool isdigit(int x)
{
if(x>='0'&&x<='9')
return true;
else
return false;
}
int StrToInt(const char *str)
{
//------系统常量-------
static const int MAX=INT_MAX/10;
static const int MAX_R=INT_MAX%10;
int num=0;
bool minus=false;
bool overflow=false;
//1.检测是否为空指针
if(str!=NULL)
{
printf("非空字符串\n");
const char *digit=str;
//2.检测字符串前存在空格则继续检测
while(isspace((int)*digit))digit++;
//3.正负号检测
if(*digit=='+')
digit++;
else if(*digit=='-')
{
digit++;
minus=true;
}
while(*digit!='\0')
{
//4.数字字符判断
if(*digit>='0'&&*digit<='9')
{
//5.溢出判断
if(num>MAX||(num==MAX&&(*digit -'0')>7))
{
//num=INT_MAX;
overflow=true;
break;
}
num=num*10+(*digit -'0');
digit++;
}
else
{
break;
}
}
}
else
{
printf("空字符串");
}
//6.修正结果为正数还是负数
if(overflow==true)
return minus==true? INT_MIN:INT_MAX;
else
return minus==true? -num:num;
}
int main(void)
{
int m,n;
char *str = "123456789.67";
char *str_t="2147483648";//NULL;
m = StrToInt(str_t);
n = atoi(str);
printf("int=%d,%d\n",n,m);
while(1);
return 0;
}#include <stdlib.h>
#include <stdio.h>
bool isspace(int x)
{
if(x=='\b'||x=='\t'||x=='\r'||x=='\f'||x=='\n'||x==' ')
return true;
else
return false;
}
bool isdigit(int x)
{
if(x>='0'&&x<='9')
return true;
else
return false;
}
int StrToInt(const char *str)
{
//------系统常量-------
static const int MAX=INT_MAX/10;
static const int MAX_R=INT_MAX%10;
int num=0;
bool minus=false;
bool overflow=false;
//1.检测是否为空指针
if(str!=NULL)
{
printf("非空字符串\n");
const char *digit=str;
//2.检测字符串前存在空格则继续检测
while(isspace((int)*digit))digit++;
//3.正负号检测
if(*digit=='+')
digit++;
else if(*digit=='-')
{
digit++;
minus=true;
}
while(*digit!='\0')
{
//4.数字字符判断
if(*digit>='0'&&*digit<='9')
{
//5.溢出判断
if(num>MAX||(num==MAX&&(*digit -'0')>7))
{
//num=INT_MAX;
overflow=true;
break;
}
num=num*10+(*digit -'0');
digit++;
}
else
{
break;
}
}
}
else
{
printf("空字符串");
}
//6.修正结果为正数还是负数
if(overflow==true)
return minus==true? INT_MIN:INT_MAX;
else
return minus==true? -num:num;
}
int main(void)
{
int m,n;
char *str = "123456789.67";
char *str_t="2147483648";//NULL;
m = StrToInt(str_t);
n = atoi(str);
printf("int=%d,%d\n",n,m);
while(1);
return 0;
}