C++ String Class

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mike_g	Created : 13 October 2007 Language : Basic C++ String Class
Heres a string class I was working on until I discovered that it was pointless considering I could use the built in C++ string class. Still it does quite a few things with strings that you can do in Blitz, and it shouldent be hard to convert a function or two to C if needed. typedef unsigned char Uint8; typedef unsigned short Uint16; typedef unsigned int Uint32; const Uint8 STRING_CLASS_UPPERCASE = 1; const Uint8 STRING_CLASS_LOWERCASE = 2; #include <cstring> #include <iostream> #include <fstream> #include <ctype.h> using namespace std; class String { public: String(); String(const char); ~String(){} void Add(char); void Add(int); void Add(float); void Set(char); void Set(int); void Set(float); void Print(Uint8); char Get(); char* GetLeft(Uint16); char* GetRight(Uint16); char* GetMid(Uint16, Uint16); char* GetWord(Uint16); int Len(); int Words(); int Sub(char, bool); void ToUpper(); void ToLower(); bool Replace(char, char, bool); void ReplaceAll(char, char, bool); bool ChopLeft(Uint16); bool ChopRight(Uint16); bool ChopMid(Uint16, Uint16); char GetChar(Uint16); void Insert(char, Uint16); void Reverse(); protected: void ItoA(char, int); void FtoA(char, float); void StrCpy(chara, charb){while(a++=b++);} void StrCat(chara, charb){while(a)a++;while(a++=b++);} Uint16 size; char str_ptr; char tmp_ptr; }; String::String() { size = 1; str_ptr = NULL; tmp_ptr = NULL; } String::String(const char src) { size = (int)strlen(src)+1; str_ptr = new char[size]; char dst = str_ptr; while(src)dst=src, dst++, src++; ++dst='\0'; tmp_ptr=NULL; } void String::Add(char add) { //Appends a new string to the existing one char origin = str_ptr; size += (int)strlen(add); str_ptr = new char[size]; char src = origin; char dst = str_ptr; while(src) {dst=src; dst++; src++;} //Copy original string while(add) {dst=add; dst++; add++;} //Copy string to append ++dst='\0'; delete[] origin; } void String::Add(int add) { //Converts an integer to a string and appends it char num[20]; ItoA(num, add); Add(num); } void String::Add(float add) { //Converts a float to a string and appends it char num[20]; FtoA(num, add); Add(num); } void String::Set(char src) { if(str_ptr) delete []str_ptr; size = (int)strlen(src)+1; str_ptr = new char[size]; char dst = str_ptr; while(src)dst=src, dst++, src++; ++dst='\0'; } void String::Set(int src) { char num[20]; ItoA(num, src); Set(num); } void String::Set(float src) { char num[20]; FtoA(num, src); Set(num); } void String::Print(Uint8 case_type=0) { //Prints the string to the screen //case_type 1 indicates uppercase //case_type 2 indicates lowercase if(!case_type) cout << str_ptr; else { char ptr = str_ptr; char string = new char[size]; while(ptr) { string=ptr; if (case_type == STRING_CLASS_UPPERCASE) string=toupper(string); else if (case_type == STRING_CLASS_LOWERCASE) string=tolower(string); string++; ptr++; } ++string='\0'; string-=size-1; cout << string; delete[] string; } } char* String::Get() { return str_ptr; } char* String::GetLeft(Uint16 chars) { if(chars >= size) return str_ptr; if(tmp_ptr) delete []tmp_ptr; tmp_ptr = new char[chars+1]; char src = str_ptr; char dst = tmp_ptr; for(int i=0; i<chars; i++) { dst = src; src++; dst++; } ++dst='\0'; return tmp_ptr; } char String::GetRight(Uint16 chars) { if(chars >= size) return str_ptr; if(tmp_ptr) delete []tmp_ptr; tmp_ptr = new char[chars+1]; char src = str_ptr; char dst = tmp_ptr; int start = size-chars-1; for(int i=0; i<start; i++, src++); while(src) { dst = src; src++; dst++; } ++dst='\0'; return tmp_ptr; } char* String::GetMid(Uint16 start, Uint16 chars) { if(chars >= size) return str_ptr; if(tmp_ptr) delete []tmp_ptr; tmp_ptr = new char[chars+1]; char src = str_ptr; char dst = tmp_ptr; for(int i=1; i<start; i++, src++); for(int i=0; i<chars; i++, src++, dst++) dst = src; ++dst='\0'; return tmp_ptr; } char String::GetWord(Uint16 index) { //Gets the nth word within a string //Returns null if there are not enough words in the string if(tmp_ptr) delete []tmp_ptr; tmp_ptr = new char[100]; char src = str_ptr; char dst = tmp_ptr; Uint16 word_count=0; Uint16 max_count=0; bool in_space = false; if(src != ' ' \|\| src == '\t') word_count++; while(src) { if(word_count != index) { if(src == ' ' \|\| src == '\t') { in_space=true; } else if(src == '\n' \|\| src == '\r') { //Ignore newlines } else if(in_space) { word_count++; if(word_count == index) dst=src, dst++; in_space = false; } } else { if(src == ' ' \|\| src == '\t' \|\| max_count > 98) break; dst = src; dst++; max_count++; } src++; } ++dst='\0'; return tmp_ptr; } int String::Len() { return size-1; } int String::Words() { //Returns the number of words seperated by spaces in the string char pos = str_ptr; int word_count=0; bool in_space = false; if(pos != ' ' \|\| pos == '\t') word_count++; while(pos) { if(pos == ' ' \|\| pos == '\t') { in_space = true; } else if(pos == '\n' \|\| pos == '\r') { //Ignore newlines } else if(in_space) { word_count++; in_space = false; } pos++; } return word_count; } int String::Sub(char sub, bool case_sensitive=true) { //Searches for a substring within the string //Returns -1 for failure or the index of first occurence bool in=false; char a='\0', b='\0'; char a_ptr=0, b_ptr=0; int found=-2; //if returns -2 then somethings wrong for(int i=0; i<size; i++) { a_ptr=&str_ptr[i]; a=a_ptr; if(!case_sensitive)a=tolower(a); if(!in) { b_ptr=sub; b=b_ptr; if(!case_sensitive)b=tolower(b); if(a == b) found=i, in=true; //Start comparison } else { b_ptr++; b=b_ptr; if(b == '\0') return found; if(!case_sensitive)b=tolower(b); if(a != b) in=false, i=found; //If not match then restart from start index } } return -1; } void String::ToUpper() { //Converts the entire string to uppercase char ptr = str_ptr; while(ptr) ptr=toupper(ptr), ptr++; } void String::ToLower() { //Converts the entire string to lowercase char ptr = str_ptr; while(ptr) ptr=tolower(ptr), ptr++; } bool String::Replace(char find, char replace, bool case_sensitive=true) { //Finds the first instance of a substring within the string and replaces it //Returns false when a match cannot be made int index = Sub(find, case_sensitive); if(index == -1) return false; int f_len = (int)strlen(find); int r_len = (int)strlen(replace); char origin = str_ptr; char src=0, dst=0; Uint16 i; size = size-f_len+r_len; str_ptr = new char[size]; src=origin; dst=str_ptr; for(i=0; i<index; i++) { dst = src; src++; dst++; } src=replace; for(i=0; i<r_len; i++) { dst = src; src++; dst++; } src=origin+index+f_len; while(src) { dst = src; src++; dst++; } ++dst='\0'; delete[] origin; return true; } void String::ReplaceAll(char find, char replace, bool case_sensitive=true) { //Replaces each occurence of a substring within a string while(Replace(find, replace, case_sensitive)); } bool String::ChopLeft(Uint16 chars) { //Truncates the string to the number of 'chars' from its left. //Returns false on error if(chars >= size) return false; char origin = str_ptr; size = chars+1; str_ptr = new char[size]; char src=origin; char dst=str_ptr; for(int i=0; i<chars; i++) { dst = src; src++; dst++; } ++dst='\0'; delete[] origin; return true; } bool String::ChopRight(Uint16 chars) { //Truncates the string to the number of 'chars' //To its right not counting the null terminator //Returns false on error if(chars >= size) return false; char origin = str_ptr; int start = size-chars-1; size = chars+1; str_ptr = new char[size]; char src=origin; char dst=str_ptr; for(int i=0; i<start; i++, src++); while(src) { dst = src; src++; dst++; } ++dst='\0'; delete[] origin; return true; } bool String::ChopMid(Uint16 start, Uint16 chars) { //Truncates string to the number of 'chars' //Begining at the start index. Indexing begins at 0 //Returns False on error if(start+chars >= size) return false; char origin = str_ptr; size = chars+1; str_ptr = new char[size]; char src=origin; char dst=str_ptr; for(int i=0; i<start; i++, src++); for(int i=0; i<chars; i++) { dst = src; src++; dst++; } ++dst='\0'; delete[] origin; return true; } char String::GetChar(Uint16 index) { //Returns the Nth char in the string starting from 0 //Returns 0 on error if(index >= size) return 0; char ptr = str_ptr; for(int i=0; i<index; i++, ptr++); return ptr; } void String::Insert(char add, Uint16 index) { //Inserts a string into the string object at given index char origin = str_ptr; size+=(int)strlen(add); str_ptr = new char[size]; char src=origin; char dst=str_ptr; for(int i=0; i<index; i++, src++, dst++) dst = src; //Copy up to index while(add) dst=add, add++, dst++; //Copy to insert while(src) dst=src, src++, dst++; //Copy from index ++dst='\0'; delete[] origin; } void String::Reverse() { int loop_until = size / 2; char left = str_ptr; char right = str_ptr+size-2; char temp; for(int i=0; i<loop_until; i++) { temp = right; right = left; left = temp; left++; right--; } } void String::ItoA(char str, int num) { //Private function converts integers to a string int i=num,p=0; while(i>0)i/=10,p++; //Get char length of number for(i=1;i<=p;i++) { str[p-i]=num%10+'0'; num/=10; } str[p]='\0'; } void String::FtoA(char* str, float num) { //Private function converts floats to a string //Get Number of decimal places int left = (int)num; //Holds the integer half of the number int right=0; //Holds the fractional half converted to integer float temp = num - left; //Holds fractional value int ones=0; //Holds 1s digit //Convert fractional value to integer while(temp > 0.1) { temp = 10; right = 10; ones = (int)temp; temp -= ones; right += ones; } //Construct string from components char temp_s[20]; ItoA(temp_s, left); StrCpy(str, temp_s); StrCat(str, "."); ItoA(temp_s, right); if(*temp_s == '\0') StrCat(temp_s, "0"); StrCat(str, temp_s); } --v

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C++ String Class

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