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String Manipulation Techniques in Cpp

String Manipulation Techniques in Cpp

Case Conversion (Upper/Lowercase)
Removing Whitespace
Splitting Strings
Joining Strings

Case Conversion (Upper/Lowercase)

In C++, you can convert strings to uppercase or lowercase using functions provided by the header or the std::transform() algorithm. Examples:

Converting to Uppercase:

#include <cctype>
#include <algorithm>
std::string str = "Hello World";
// Using toupper() function from <cctype> header 
for (char& c: str) {
    c = std::toupper(c);
}
// Using std::transform() algorithm
    std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c) { return std::toupper(c);
});

Converting to Lowercase:

#include <cctype> 
#include <algorithm>
std::string str = "Hello World";
// Using tolower() function from <cctype> header
for (char& c : str) { 
    c = std::tolower(c);
}
// Using std::transform() algorithm 
    std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c) { return std::tolower(c);
});

Removing Whitespace

To remove whitespace (spaces, tabs, newlines) from a string in C++, you can use various techniques, such as using the std::remove_if() algorithm with a predicate or utilizing the erase-remove idiom. Examples:

Removing Whitespace using std::remove_if():

#include <algorithm>
#include <cctype>
std::string str = "  Hello World  ";
str.erase(std::remove_if (str.begin(), str.end, [](unsigned char c) { 
    return std::isspace(c);
}), str.end());

Removing Whitespace using the erase-remove idiom:

std::string str = "  Hello  World  ";
str.erase(std::remove(str.begin(), str.end(), '), str.end());

Splitting Strings

To split a string into multiple substrings based on a delimiter in C++, you can use functions like std::getline(), std::istringstream, or utilize the std::regex library. Examples:

Splitting a string using std::getline():

#include <sstream>
#include <vector>
std::string str = "Hello, World, How, Are, You"; 
std::vector<std::string> tokens;
std::istringstream iss(str);
std::string token;
while (std::getline(iss, token, ',')) { 
    tokens.push_back(token);
}

Splitting a string using std::istringstream:

#include <sstream>
#include <vector>
std::string str = "Hello World How Are You"; 
std::vector<std::string> tokens;
std::istringstream iss(str); 
std::string token;
while (iss >> token) {
    tokens.push_back(token);
}

Joining Strings

To join multiple strings together in C++, you can use the + operator, std::stringstream, or the std::accumulate() algorithm. Examples:

Joining strings using the + operator:

#include <vector>
#include <string>
std::vector<std::string> words = {"Hello", "World", "How", "Are", "You"}; 
std::string joinedString;
for (const std::string& word: words) {
    joinedString += word;
}
// Result: "HelloWorldHowAreYou"

Joining strings using std::stringstream:

#include <vector>
#include <string>
#include <sstream>
std::vector<std::string> words = {"Hello", "World", "How", "Aze", "You"}; 
std::stringstream ss;
for (const std::string& word: words) {
    ss << word;
}
std::string joinedString = ss.str();
// Result: "HelloWorldHowAreYou"