C++ easily implements the mutual conversion of strings and character arrays

introduction

This article focuses on different ways to convert strings to char arrays and convert char arrays to strings in C++.

1. Convert strings to char arrays

C++ provides the following techniques for converting strings into char arrays:

Use the c_str() and strcpy() functions.
Use a for loop.

1.1. c_str() and strcpy() functions in C++

The C++ function c_str() and the C++ string function strcpy() can be used to easily convert strings into character arrays.

c_str()Method represents a sequence of characters in a string array followed by an empty character'\0'. It returns a null pointer to the string.

grammar:

string-name.c_str();

First use the c_str() method to get all characters of the string and terminate null characters.
Additionally, declare an empty array of type char to store the results, i.e. converting the string to the result of the char array.
Finally, usestrcpy()Method willc_str()The character sequence generated by the method is copied into an empty char array.

Example:

#include <bits/stdc++.h> 
using namespace std; 

int main() 
{ 
	 
	string str = "";
	cout<<"Enter the string:\n";
	
	cin>>str;

	char arr[() + 1]; 

	strcpy(arr, str.c_str()); 
    cout<<"String to char array conversion:\n";
	for (int i = 0; i < (); i++) 
		cout << arr[i]; 

	return 0; 
}

1.2. Conversion of strings to character arrays in a for loop

To convert a char array to a string, you can use a C++ for loop.

First create an empty array of type char.
Then iterate over the input string.
Store characters into char array when iterating.

Example:

#include <bits/stdc++.h> 
using namespace std; 

int main() 
{ 
	 
	string str = "";
	cout<<"Enter the string:\n";
	
	cin>>str;

	char arr[() + 1]; 
    cout<<"String to char array conversion:\n";
    for (int x = 0; x < sizeof(arr); x++) { 
        arr[x] = str[x]; 
        cout << arr[x]; 
    } 

	return 0; 
}

2. Convert char array to string

Techniques for converting char arrays to strings in C++:

The "+" operator.
C++ overloads the "=" operator.
C++ built-in constructor.

2.1. C++ operator ‘+’

C++ provides the function of connecting or adding data items to variables:'+' operator。

Create a new empty string to store the result.
Next, use the for loop to iterate through the input char array.
During the process of traversing the array, use the ‘+’ operator to concatenate the characters to the string.

Example:

#include <bits/stdc++.h> 
using namespace std; 


int main() 
{ 
	char arr[] = { 'L', 'I', 'O', 'N', 'L', 'O', 'N', 'G'}; 
	
	int size_arr = sizeof(arr) / sizeof(char); 
	string str = ""; 
	for (int x = 0; x < size_arr; x++) { 
		str = str + arr[x]; 
	} 
	cout<<"Converted char array to string:\n";
	cout << str << endl; 
	return 0; 
}

Output:

Converted char array to string:
LIONLONG

2.2. C++ overload the '=' operator

C++ has the concept of overloading, which allows the operator to perform other operations than basic or default operations.

Create a new empty string.
use'=' operator overloadStore data items character by character to the newly created empty string.

Example:

#include <bits/stdc++.h> 
using namespace std; 


int main() 
{ 
	char arr[] = { 'L', 'I', 'O', 'N', 'L', 'O', 'N', 'G'}; 
	
	int size_arr = sizeof(arr) / sizeof(char); 
	string str = ""; 
	str = arr;
	cout<<"Converted char array to string:\n";
	cout << str << endl; 
	return 0; 
}

Output:

Converted char array to string:
LIONLONG

2.3. C++ string built-in constructor

In the context of converting a char array to a string, you can use the C++ string constructor.

grammar:

string string-name(char array-name);

This constructor takes a sequence of characters ending with null characters as input parameters.

Note: This can only be used when declaring strings throughout the program.

Example:

#include <bits/stdc++.h> 
using namespace std; 

int main() 
{ 
	char arr[] = { 'L', 'I', 'O', 'N', 'L', 'O', 'N', 'G'}; 
	int size_arr = sizeof(arr) / sizeof(char); 
	string str(arr);
	cout<<"Converted char array to string:\n";
	cout <<str<< endl; 
	return 0; 
}

Output:

Converted char array to string:
LIONLONG

3. Summary

In this article, we learn about various techniques for converting strings to char arrays in C++ and vice versa.

This is the article about C++'s easy conversion of strings and character arrays. For more related contents of C++ strings and character arrays, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!