Size of string in C++
Introduction:
A string is a dynamic data structure in C++ that holds a list of characters. String objects are very flexible for managing text data since they have the ability to dynamically increase or shrink in size, unlike typical character arrays. Comprehending a string's length is essential for effective memory management and enhancing software efficiency.
The quantity of memory that a string takes up in the memory of a computer is indicated by its size. This comprises not just the letters themselves but also any additional memory that is utilized for accounting, including the string's length and any possible alignment or padding. The length of the text that is contained in a string, the fundamental implementation, and the particular compiler being used can all affect how big a string is in reality.
The size of string objects is something that developers need to be mindful of, particularly when working with big text volumes or when memory is limited. Smarter resource allocation and avoidance of possible problems like buffer overflows and excessive memory usage are made possible by this information. Furthermore, knowing a string's length helps you choose the algorithms and data structures wisely, which guarantees successful computations on strings in C++.
Methods for determining the length of the string:
- There are different methods to determine the length of the string:
- Using string::size
- Using string::length
- Using the predefined strlen() library function
- Using the while loop:
- Using the for loop:
1. Using string::size
To determine the length of the string using the string::size, the following program should be written:
Program:
#include <iostream> #include <string.h> using namespace std; int main() { string input_string = "JavaTPoint"; cout << "Length of input string is : " << input_string.size(); return 0; }
Output:
2. Using string::length
To determine the length of the string using the string::length, the following program should be written:
Program:
#include <iostream> #include <string.h> using namespace std; int main() { string input_string = "JavaTPoint"; cout << "Length of input string is : " << input_string.size(); return 0; }
Output:
- The string::length method is the same as the string::size, and both will get the same result, in which the result is in bytes.
3. Using strlen() function:
To determine the length of the string using the predefined library function strlen(), the following program should be written:
Program:
#include <iostream> #include <string.h> using namespace std; int main() { string input_string = "JavaTpoint Lecture"; cout << "Length of input string is : " << strlen(input_string.c_str()); return 0; }
Output:
4. Using the while loop:
To determine the length of the string using the while loop, the following program should be written, and when we are using the while loop, set the counter's initial value to zero and increase it from the string's starting to its end (till the last null character).
Program:
#include <iostream> #include <string.h> using namespace std; int main() { string input_string = "Welcome to C++ Lecture" ; int j = 0; while (input_string[j]) { j++; } cout << "Length of the input string is : " << j ; return 0; }
Output:
5. Using the for loop:
To determine the length of the string using the string::length, the following program should be written, and when we are using the for loop, set the counter's initial value to zero and increase it from the string's starting to its end (till the last null character).
Program:
#include <iostream> #include <string.h> using namespace std; int main() { int k; string input_string = "Hello World!"; for (k = 0; input_string[k]; k++); cout << "Length of the input string is : " << k ; return 0; }
Output:
Time complexity: Because we must walk over the whole string to determine its length, the time complexity for all of the approaches is O(n).
Space complexity: Since no additional space is needed, the space complexity of all the techniques is O(1).
Conclusion:
There are several ways in which one can find the length of thestring in C++. First off, there are simple methods for retrieving the length of a string objects using the "string::size" and "string::length" member functions. For null-terminated character arrays, the "strlen()" standard function can be used instead. The use of loops is an additional method. The length of a string may be found by iterating over its characters with the "while" loop until it reaches the null character. To cycle over the characters and increase the count until the last character is reached, a "for" loop may be utilized in a similar manner. Because of its flexibility and ability to be selected according to the particular needs of the application, each of these techniques makes C++ a flexible language for working with string data.