字元串操作( 三 ) _生活百科

9、strrev()功能：串倒转。用法：char *strrev(char *str);举例如下：#include <string.h> #include <stdio.h>int main(void) { char *forward = "string"; printf("Before strrev(): %s\n", forward); strrev(forward); printf("After strrev(): %s\n", forward); return 0; } 10、strtod ()功能：将字元串转换为double型值。用法：double strtod(char *str, char **endptr);举例如下：#include <stdio.h> #include <stdlib.h>int main(void) { char input[80], *endptr; double value; printf("Enter a floating point number:"); gets(input); value = strtod(input, &endptr); printf("The string is %s the number is %lf\n", input, value); return 0; }11、 strtol()功能：将串转换为长整数。用法：long strtol(char *str, char **endptr, int base);举例如下：#include <stdlib.h> #include <stdio.h>int main(void) { char *string = "87654321", *endptr; long lnumber; /* strtol converts string to long integer */ lnumber = strtol(string, &endptr, 10); printf("string = %s long = %ld\n", string, lnumber); return 0; } 12、 strupr()功能：将串中的小写字母转换为大写字母。用法： char *strupr(char *str);举例如下：#include <stdio.h> #include <string.h>int main(void) { char *string = "abcdefghijklmnopqrstuvwxyz", *ptr; /* converts string to upper case characters */ ptr = strupr(string); printf("%s\n", ptr); return 0; } 13、swab()功能：交换位元组。用法：void swab (char *from, char *to, int nbytes);举例如下：#include <stdlib.h> #include <stdio.h> #include <string.h>char source[15] = "rFna koBlrna d"; char target[15];int main(void) { swab(source, target, strlen(source)); printf("This is target: %s\n", target); return 0; } C++字元串操作选用C++标準程式库中的string类，是因为他和c-string比较起来，不必担心记忆体是否足够、字元串长度等等，而且作为一个类出现，他集成的操作函式足以完成我们大多数情况下的需要。1、字元串赋值使用=,assign()，“=”的用法不作详细说明,assign用法如下：# include <iostream># include <string>using namespace std;int main(){ string str1 = "yesterday once more"; string str2 ("my heart go on"); string str3,str4; str3.assign(str2,3,6); // = heart str4.assign(str2,3,string::npos); // = heart go on (从2开始到结尾赋给str4) str4.assign("gaint"); // =gaint str4.assign("nico",5); // = nico str4.assign(5,'x'); // cout<<str4<<endl; getchar(); return 0; }