VC字符串处理整理

场景:

1.在存储数据时有时接口需要合并字符串值,并以某些特殊字符来合并部分，到需要的时候再分割它。如一些数值,人名等。

2.C++有strtok,stringstream和find函数来实现分割。可以根据情况调用。

#include <stdlib.h>
#include <string.h>
#include
#include <iostream>
#include <sstream>
#include <vector>
using namespace std;

void TestStrtok()
{
    //1.非线程安全的,如果多个线程同时调用,会覆盖掉原来的值.
    //2.支持以字符串分割.
    //3.源字符串必须是可修改的.
    char c_str[]="google||twitter||facebook||microsoft||apple||ibm||";
    const char* delim = "||";
    char* result = strtok(c_str,delim);
    while(result != NULL)
    {
        cout << result << endl;
        result = strtok(NULL,delim);
    }
}

void TestGetLineWithStringStream()
{
    //1.线程安全的,但是只能以字符作为分隔符
    stringstream ss("google|twitter|facebook|microsoft|apple|ibm|");
    string str;
    while(getline(ss,str,'|'))
    {
        cout << str << endl;
    }
}

void TestStringFind()
{
    //1.自己实现,线程安全,支持字符串作为分隔符.缺点可能就是代码量多.
    string str = "google||twitter||facebook||microsoft||apple||ibm||";
    const char* delim = "||";
    const int len = strlen(delim);
    size_t index = ;
    size_t pos = str.find(delim,index);
    while(pos != string::npos)
    {
        string ss = str.substr(index,pos-index);
        cout << ss << endl;
        index = pos+len;
        pos = str.find(delim,index);
    }

    //cout << "is last?" << " index:" << index << " str.length():" << str.length() << endl;
    if((index+) < str.length())
    {
        string ss = str.substr(index,str.length() - index);
        cout << ss << endl;
    }
}

int main(int argc, char const *argv[])
{
    cout << "TestStrtok: " << endl;
    TestStrtok();
    cout << "TestGetLineWithStringStream: " << endl;
    TestGetLineWithStringStream();
    cout << "TestStringFind: " << endl;
    TestStringFind();

    return ;
}

输出:

TestStrtok:

google

twitter

facebook

microsoft

apple

ibm

TestGetLineWithStringStream:

google

twitter

facebook

microsoft

apple

ibm

TestStringFind:

google

twitter

facebook

microsoft

apple

ibm

[Finished in 0.2s]

 

char* a[3];
char* buf ="这是第一行\n这是第二行\n这是第三行\n";

我想要用'\n'符将buf分割成三段并分别存入a[1]，a[2]，a[3]中，
请问该怎么做～

#include <stdio.h>
#include <string.h>
#include <malloc.h>

int main()
{
 char *a[];
 char *buf ="这是第一行\n这是第二行\n这是第三行\n";
 char *t, *pre = buf;
 int i = , l;

 while (t = strchr(pre, '\n'))
 {
  if (i >= )
   break;

  l = t - pre;
  a[i] = (char *)malloc(l + );
  strncpy(a[i], pre, l);
  a[i][l] = '\0';
  ++i;
  pre = t + ;
 }

 for (i = ; i < ; ++i)
 {
  printf("%s\n", a[i]);
  free(a[i]);
 }

 return ;
}