#include<stdio.h> //法1：字串賦值 void Mystrcpy(char des,charsrc) { int i; for(i=0;src[i]!=’\0’;i++) { des[i]=src[i]; } des=’\0’; }

//法2：void Mystrcpy2(char des,charsrc) {

for(;*src!='\0';src++,des++)
{
	*des=*src;
}
*des='\0';

}

： //法三void Mystrcpy3(char des,charsrc) { while(*src!=’\0’)

{
	*des=*src;
	src++;
	des++;
}
*des='\0';
 

}

//法四： void Mystrcpy4(char des,charsrc) { while(*des++=*src++) ;

} //字串轉數字

int Stonum(const char arr[]) { int sum = 0; for (int i = 0; ; i++) { if (isalnum(arr[i])!=2) { if (sum != 0) { sum = sum * 10 + arr[i]-‘0’; } else { sum += arr[i] - ‘0’; } } else { return sum; } }

}

//數字轉字串 void Numtos(int num) { char arr[100]; int mark = 1; int tmp = num; for (int i = 0; tmp > 9; i++) { tmp /= 10; mark *= 10; } int j; for ( j = 0; num > 0; j++) { arr[j] = num / mark+‘0’; num = num%mark; mark /= 10; } arr[j] = ‘\0’;

puts(arr);

}

int main() { char str1[100]=“xyz”; char str2[100]=“abcde”; Mystrcpy4(str1,str2); printf("%s",str1); int num = 123456; Numtos(num); char arr[] = “1245ax68”; printf("%d\n",Stonum(arr));

return 0;

}