how to use string in c++ code example
Example 1: how can make string value in cpp
#include <string>
string hello= "hello you thre :)";
Example 2: string in cpp
// Include the string library
#include <string>
// Create a string variable
string greeting = "Hello";
Example 3: declaring strings c++
std::string str = "hello world";
char *str = "hello world";
char str[] = "hello world";
char str[11] = "hello world";
Example 4: string in c++
#include <iostream>
#include <string>//for printing std::string
int main()
{
//A string is a group of characters and an array of const chars
const char* name = "Caleb";//C style string
//how string actually works below:
//String without null terminating character below:
char name2[5] = { 'C','a','l','e','b' };// string is just an array of characters
//The above doesn't have an null termination character at the end cout will not now where the string ends and will acess memory that is not a part of your string
std::cout << name2 << std::endl;//output => Caleb + somejunk //this is because null terminating char is not present at the end of array
//String with null terminating character below:
char name3[6] = { 'C','a','l','e','b','\0' };//null terminating char '\0' or '0' can be used
std::cout << name3 << std::endl;//output => Caleb // because null terminating char is present cout knows where array ends
//std::string class in c++ is takes an array of const chars and a bunch of functions to manuplate it:
//std::string has a constructor that takes const char array
std::string name4 = "Caleb";
name4.size();//gives size of string and there are many more methods in std::string class
//appending to std::string
//"Ever thing inside these double quotes becomes const char array"
//std::string namee = "Caleb" +"Hello";//This will give error because adding const char array to const char array
std::string namee = "Caleb";
namee += " Hello";//This will work because adding a ptr to a actual string
std::cout << namee << std::endl;
//You can also use the below
std::string namee2 = std::string("Caleb")+" Hello";// This will work because constructor will convert const char array to string, adding a ptr to string
std::cout << namee2 << std::endl;
std::cin.get();
}
Example 5: c++ string
#include <string>
std::string myString = "Hello, World!";
Example 6: c++ string
#include <string>
#include <iostream>
#include <type_traits>
#include <cstring>
int main() {
std::string str = "Hello, there";
std::cout << std::boolalpha
<< str.capacity() << ", " << str.size() << ", " << std::strlen(str.data()) // 12, 12, 12
<< '\n' << std::is_same_v<std::string, std::basic_string<char>> // true
<< '\n' << str.front() + str.substr(1, 10) + str.back() // Hello there
<< '\n' << str[0] // H
<< '\n';
str += "!";
std::cout << str << '\n'; // Hello, there!
str.erase(4, 4); // Hellhere!
str.pop_back(); // Hellhere
str.insert(4, " "); // Hell here
std::cout << str << '\n'; // Hell here
}