011 C语言基础

//   101.c
#include<stdio.h>
void fun(char a[],char b[])
{
   while(*a)a++;
   while(*b)*a++=*b++;
}
void main()
{
    char a[20]="china",b[]="qiyang";
    fun(a,b);
    puts(a);
    getch();
}

//   102.c
#include<stdio.h>
#include<string.h>
void main()
{
   char a[20],b[]="thisisabook";
   strcpy(a,b);
   puts(a);
   getch();
}

//  103.c
#include<stdio.h>
void cpyfun(char a[],char b[])
{
   //while(*b)*a++=*b++;
   //*a=0;
   int i;
   for(i=0;b[i];i++)
     a[i]=b[i];
   a[i]=0;
}
void main()
{
   char a[20],b[]="this\0isabook";
   cpyfun(a,b);
   puts(a);
   getch();
}

//  104.c
#include<stdio.h>
#include<string.h>
int cmpfun(char a[],char b[])
{
   int i=0;
   while(a[i]==b[i]&&a[i]&&b[i])i++;
   return a[i]-b[i];
}
void main()
{
   printf("%d",cmpfun("chinab","china"));
   getch();
}

//  105.c
#include<stdio.h>
#include<string.h>
int cmpfun(char a[],char b[])
{
   while(*a==*b&&*a&&*b){a++;b++;}
   return *a-*b;
}
void main()
{
   printf("%d",cmpfun("china","chinb"));
   getch();
}

// 106.c
#include<stdio.h>
#include<string.h>
int cmpfun(char a[],char b[])
{
   if(*a==0&&*b==0)return 0;
   if(*a!=*b)return *a-*b;
   return cmpfun(a+1,b+1);
}
void main()
{
   printf("%d",cmpfun("china","chinb"));
   getch();
}

// 107.c
#include<stdio.h>
#include<string.h>
void main()
{
    char a[]="HuNanQiYang";//驼峰式写法
    strupr(a);
    puts(a);
    getch();
}

// 108.c
#include<stdio.h>
void uprfun(char a[])
{
    int i=0;
    while(a[i])
    {
       if(a[i]>='a'&&a[i]<='z')a[i]=a[i]-32;
       i++;
    }
}
void main()
{
    char a[]="HuNanQiYang";//驼峰式写法
    uprfun(a);
    puts(a);
    getch();
}

// 109.c
#include<stdio.h>
void uprfun(char a[])
{
    while(*a)
    {
      if(*a>='a'&&*a<='z')*a=*a-32;
      a++;
    }
}
void main()
{
    char a[]="HuNanQiYang";//驼峰式写法
    uprfun(a);
    puts(a);
    getch();
}

//  110.c
#include<stdio.h>
void uprfun(char a[])
{
    if(*a==0)return;
    if(*a>='a'&&*a<='z')*a=*a-32;
    return uprfun(a+1);
}
void main()
{
    char a[]="HuNanQiYang";//驼峰式写法
    uprfun(a);
    puts(a);
    getch();
}