string operations in c++ code example
Example 1: string in cpp
// Include the string library
#include <string>
// Create a string variable
string greeting = "Hello";
Example 2: 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 3: c++ string
#include <string>
std::string myString = "Hello, World!";
Example 4: string in cpp
// you want to include <string>
#include <string>
#include <iostream>
int main()
{
string helloWorld = "Hello World!"; // creating string and assigning
std::cout << helloWorld; // will output what you assigned it!
/* you can also use strings with user
input (cin/getline)*/
string namePerson{};
getline(cin, namePerson); // getline allows for multi word input
std::cout << namePerson; // outputs name which person inputted
}
Example 5: c++ string manipulation
/*
OUTPUT
String value: Programming {where applicable: -31.05}
-----------------------------------------------------------------------------
|Programming| << [No manipulation]
| Programming| << [Width:20][align:string_default=right]
| Programming| << [Width:20][align:right]
|Programming | << [Width:20][align:left]
|-31.05 | << [Width:20][align:int_default=left]
|- 31.05| << [Width:20][align:internal]
|.........Programming| << [Width:20][align:default][fill:.]
|+++++++++Programming| << [Width:20][align:default][fill:+]
|=========Programming| << [Width:20][align:default][fill:=]
-----------------------------------------------------------------------------
*/
string sString = "Programming"; // Length = 11
//NOTE: always place the settings before the actual string in cout
// width
cout << "|" << sString << "|" << "\t\t << [No manipulation]" << endl;
cout << "|" << setw(20) << sString << "|" << "\t << [Width:20][align:string_default=right]\n";
// alignment
cout << "|" << setw(20) << right << sString << "|" << "\t << [Width:20][align:right]\n";
cout << "|" << setw(20) << left << sString << "|" << "\t << [Width:20][align:left]\n";
cout << "|" << setw(20) << -31.05 << "|" << "\t << [Width:20][align:int_default=left]\n";
cout << "|" << setw(20) << internal << -31.05 << "|" << "\t << [Width:20][align:internal]\n";
// fill (HAVE to use single quotes in the setfill argument definition)
cout << "|" << setw(20) << setfill('.') << sString << "|" << "\t << [Width:20][align:default][fill:.]\n";
cout << "|" << setw(20) << setfill('+') << sString << "|" << "\t << [Width:20][align:default][fill:+]\n";
cout << "|" << setw(20) << setfill('=') << sString << "|" << "\t << [Width:20][align:default][fill:=]\n";