C++ || How To Trim & Remove The Leading & Trailing Whitespace From A String Using C++

December 10, 2020 admin No comments

The following is a module with functions which demonstrates how to trim and remove the leading and trailing whitespace from a string using C++.

1. Trim

The example below demonstrates the use of ‘Utils::trim‘ to remove all the leading and trailing whitespace characters from a string.





		
		
			1. Trim
			
C++
			
			// Trim

// Declare string
std::string original = "  <-Kenneth->  ";

// Trim the string
auto trim = Utils::trim(original);

// Display result
std::cout << "Original: '" << original << "'" << std::endl;
std::cout << "Trim: '" << trim << "'" << std::endl;

// expected output:
/*
    Original: '  <-Kenneth->  '
    Trim: '<-Kenneth->'
*/
			
				
					
				
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						// Trim
 
// Declare string
std::string original = "  <-Kenneth->  ";
 
// Trim the string
auto trim = Utils::trim(original);
 
// Display result
std::cout << "Original: '" << original << "'" << std::endl;
std::cout << "Trim: '" << trim << "'" << std::endl;
 
// expected output:
/*
    Original: '  <-Kenneth->  '
    Trim: '<-Kenneth->'
*/

2. Trim Start

The example below demonstrates the use of ‘Utils::trimStart‘ to remove all leading whitespace characters from a string.





		
		
			2. Trim Start
			
C++
			
			// Trim Start 

// Declare string
std::string original = "  <-Kenneth->  ";

// Trim the start of string
auto ltrim = Utils::trimStart(original);

// Display result
std::cout << "Original: '" << original << "'" << std::endl;
std::cout << "Trim Start: '" << ltrim << "'" << std::endl;

// expected output:
/*
    Original: '  <-Kenneth->  '
    Trim Start: '<-Kenneth->  '
*/
			
				
					
				
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						// Trim Start 
 
// Declare string
std::string original = "  <-Kenneth->  ";
 
// Trim the start of string
auto ltrim = Utils::trimStart(original);
 
// Display result
std::cout << "Original: '" << original << "'" << std::endl;
std::cout << "Trim Start: '" << ltrim << "'" << std::endl;
 
// expected output:
/*
    Original: '  <-Kenneth->  '
    Trim Start: '<-Kenneth->  '
*/

3. Trim End

The example below demonstrates the use of ‘Utils::trimEnd‘ to remove all trailing whitespace characters from a string.





		
		
			3. Trim End
			
C++
			
			// Trim End

// Declare string
std::string original = "  <-Kenneth->  ";

// Trim the end of string
auto rtrim = Utils::trimEnd(original);

// Display result
std::cout << "Original: '" << original << "'" << std::endl;
std::cout << "Trim End: '" << rtrim << "'" << std::endl;

// expected output:
/*
    Original: '  <-Kenneth->  '
    Trim End: '  <-Kenneth->'
*/
			
				
					
				
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						// Trim End
 
// Declare string
std::string original = "  <-Kenneth->  ";
 
// Trim the end of string
auto rtrim = Utils::trimEnd(original);
 
// Display result
std::cout << "Original: '" << original << "'" << std::endl;
std::cout << "Trim End: '" << rtrim << "'" << std::endl;
 
// expected output:
/*
    Original: '  <-Kenneth->  '
    Trim End: '  <-Kenneth->'
*/

4. Utils Namespace

The following is the Utils Namespace. Include this in your project to start using!





		
		
			Utils Namespace
			
C++
			
			// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Dec 10, 2020
//    Taken From: http://programmingnotes.org/
//    File:  Utils.h
//    Description: Handles general utility functions
// ============================================================================
#pragma once
#include <string>
#include <algorithm>
#include <cctype>

namespace Utils {
    /**
    * FUNCTION: trimEnd 
    * USE: Returns a new string with all trailing whitespace characters removed
    * @param source: The source string
    * @return: A new string with all the trailing whitespace characters removed
    */
    std::string trimEnd(std::string source) {
        source.erase(std::find_if(source.rbegin(), source.rend(), [](char c) {
            return !std::isspace(static_cast<unsigned char>(c));
        }).base(), source.end());
        return source;
    }

    /**
    * FUNCTION: trimStart 
    * USE: Returns a new string with all leading whitespace characters removed
    * @param source: The source string
    * @return: A new string with all the leading whitespace characters removed
    */
    std::string trimStart(std::string source) {
        source.erase(source.begin(), std::find_if(source.begin(), source.end(), [](char c) {
            return !std::isspace(static_cast<unsigned char>(c));
        }));
        return source;
    }

    /**
    * FUNCTION: trim 
    * USE: Returns a new string with all the leading and trailing whitespace 
    *   characters removed
    * @param source: The source string
    * @return: A new string with all the leading and trailing whitespace 
    *   characters removed
    */
    std::string trim(std::string source) {
        return trimEnd(trimStart(source));
    }
}// http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Dec 10, 2020
//    Taken From: http://programmingnotes.org/
//    File:  Utils.h
//    Description: Handles general utility functions
// ============================================================================
#pragma once
#include <string>
#include <algorithm>
#include <cctype>
 
namespace Utils {
    /**
    * FUNCTION: trimEnd 
    * USE: Returns a new string with all trailing whitespace characters removed
    * @param source: The source string
    * @return: A new string with all the trailing whitespace characters removed
    */
    std::string trimEnd(std::string source) {
        source.erase(std::find_if(source.rbegin(), source.rend(), [](char c) {
            return !std::isspace(static_cast<unsigned char>(c));
        }).base(), source.end());
        return source;
    }
 
    /**
    * FUNCTION: trimStart 
    * USE: Returns a new string with all leading whitespace characters removed
    * @param source: The source string
    * @return: A new string with all the leading whitespace characters removed
    */
    std::string trimStart(std::string source) {
        source.erase(source.begin(), std::find_if(source.begin(), source.end(), [](char c) {
            return !std::isspace(static_cast<unsigned char>(c));
        }));
        return source;
    }
 
    /**
    * FUNCTION: trim 
    * USE: Returns a new string with all the leading and trailing whitespace 
    *   characters removed
    * @param source: The source string
    * @return: A new string with all the leading and trailing whitespace 
    *   characters removed
    */
    std::string trim(std::string source) {
        return trimEnd(trimStart(source));
    }
}// http://programmingnotes.org/

5. More Examples

Below are more examples demonstrating the use of the ‘Utils‘ Namespace. Don’t forget to include the module when running the examples!





		
		
			More Examples
			
C++
			
			// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Dec 10, 2020
//    Taken From: http://programmingnotes.org/
//    File:  program.cpp
//    Description: The following demonstrates the use of the Utils Namespace
// ============================================================================
#include <iostream>
#include <string>
#include <exception>
#include "Utils.h"

void display(const std::string& message);

int main() {
    try {
        // Declare string
        std::string original = "  <-Kenneth->  ";

        // Trim the string
        auto trim = Utils::trim(original);

        // Display result
        display("Original: '" + original + "'");
        display("Trim: '" + trim + "'");

        display("");

        // Trim the start of string
        auto ltrim = Utils::trimStart(original);

        // Display result
        display("Original: '" + original + "'");
        display("Trim Start: '" + ltrim + "'");

        display("");

        // Trim the end of string
        auto rtrim = Utils::trimEnd(original);

        // Display result
        display("Original: '" + original + "'");
        display("Trim End: '" + rtrim + "'");
    } catch (std::exception& e) {
        display("\nAn error occurred: " + std::string(e.what()));
    }

    std::cin.get();
    return 0;
}

void display(const std::string& message) {
    std::cout << message << std::endl;
}// http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Dec 10, 2020
//    Taken From: http://programmingnotes.org/
//    File:  program.cpp
//    Description: The following demonstrates the use of the Utils Namespace
// ============================================================================
#include <iostream>
#include <string>
#include <exception>
#include "Utils.h"
 
void display(const std::string& message);
 
int main() {
    try {
        // Declare string
        std::string original = "  <-Kenneth->  ";
 
        // Trim the string
        auto trim = Utils::trim(original);
 
        // Display result
        display("Original: '" + original + "'");
        display("Trim: '" + trim + "'");
 
        display("");
 
        // Trim the start of string
        auto ltrim = Utils::trimStart(original);
 
        // Display result
        display("Original: '" + original + "'");
        display("Trim Start: '" + ltrim + "'");
 
        display("");
 
        // Trim the end of string
        auto rtrim = Utils::trimEnd(original);
 
        // Display result
        display("Original: '" + original + "'");
        display("Trim End: '" + rtrim + "'");
    } catch (std::exception& e) {
        display("\nAn error occurred: " + std::string(e.what()));
    }
 
    std::cin.get();
    return 0;
}
 
void display(const std::string& message) {
    std::cout << message << std::endl;
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

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Posted in: Advanced, C++ Tags: c++, string, trim

C++ || How To Trim & Remove The Leading & Trailing Whitespace From A String Using C++

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