Lecture 127:- Let's Put all together in C++ program for array

Strings are a fundamental data type in computer programming used to represent sequences of characters. In most programming languages, including C++ and C, strings are represented as an array of characters terminated by a null character '\0'. Each character in the string is associated with an ASCII value that corresponds to the character.

Strings are commonly used to store textual data such as words, sentences, and even complete paragraphs. They are essential for tasks involving input/output, text processing, and manipulation. Here are some key points about strings:

1. Character Array: In C and C++, strings are represented as character arrays, where each element of the array contains one character of the string, and the last element is the null character ('\0') to indicate the end of the string.
2. String Literals: String literals are sequences of characters enclosed in double quotes. For example, "Hello, World!" is a string literal.
3. String Library: In C++, the Standard Template Library (STL) provides the std::string class, which offers a more convenient and powerful way to work with strings. The std::string class takes care of memory management and provides various member functions to manipulate strings.
4. Operations: Strings support various operations like concatenation (combining two strings), comparison (checking if two strings are equal), finding the length of the string, and extracting substrings.
5. Null-Terminated: In C, strings are null-terminated, meaning that the null character ('\0') is used to mark the end of the string. It is crucial to ensure that enough space is allocated for the entire string, including the null character.

Here's an example of using strings in C++:

cppCopy code

#include <iostream> #include <string> int main() {    // Using character arrays    char str1[] = "Hello";    char str2[10] = "World";    char str3[20];    strcpy(str3, str1);    strcat(str3, " ");    strcat(str3, str2);    std::cout << "Concatenated string: " << str3 << std::endl;    // Using std::string class    std::string greeting = "Hello, World!";    std::cout << "Length of the string: " << greeting.length() << std::endl;    return 0; }

In this example, we demonstrate the usage of character arrays (str1, str2, and str3) and the std::string class (greeting). The program concatenates the strings and calculates the length of the greeting string using the std::string member function length().

Remember that in C++, it is generally recommended to use std::string for string manipulation, as it provides better safety and ease of use compared to raw character arrays.