构造函数的实现 String:: String( char *str) { len=o while(str[len]=0) len+十 value= new char[len+1] for(i=0; i<len+1; i++) value[i]=str[i]构造函数的实现 String::String(char *str) { len=0; while(str[len]!='\0') { len++; } value= new char[len+1]; for(i=0; i<len+1; i++) value[i]=str[i]; }