String

Container for storing elements of type char

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Contents

Definition
Description
Member Functions
Page Comments

Key Facts

Gyroscopic Couple: The rate of change of angular momentum ( $\inline \tau$ ) = $\inline I\omega\Omega$ (In the limit).

$\inline I$ = Moment of Inertia.
$\inline \omega$ = Angular velocity
$\inline \Omega$ = Angular velocity of precession.

Blaise Pascal (1623-1662) was a French mathematician, physicist, inventor, writer and Catholic philosopher.

Leonhard Euler (1707-1783) was a pioneering Swiss mathematician and physicist.

Definition

The std::string class template is defined in the standard header <string>, and in the nonstandard backward-compatibility header <string.h>.

namespace std {
            typedef basic_string<char> string;
}

Description

The class template basic_string stores and manipulates sequences of type char. std::string is an STL container which is part of basic_string for storing elements of type char.

Member Functions

Operation	Description
`constructor`	Create or copy a string
`destructor`	Destroys a string
=, assign()	Assign a new value
swap()	Swaps values between two strings
+=, append(), push_back()	Append characters
insert()	Inserts characters
erase()	Deletes characters
resize()	Changes the number of characters (deletes or appends characters at the end)
replace()	Replaces characters
+	Concatenates strings
==, !=, <, <=, >, >=, compare()	Compare strings
size(), length()	Return the number of characters
max_size()	Returns the maximum possible number of characters
empty()	Returns if the string is empty
capacity()	Returns the number of characters that can held without be reallocation
[], at()	Access a character
>>, getline()	Read the value from a stream
<<	Writes the value to a stream
copy()	Copies or writes the contents to a C-string
c_str()	Returns the value as C-string
data()	Returns the value as character array
substr()	Returns a certain substring
get_allocator()	Returns the allocator

Iterators

Operation	Description
begin(), cbegin()	Returns an iterator to the beginning
end(), cend()	Returns an iterator to the end
rbegin(), crbegin()	Returns a reverse iterator to the beginning
rend(), crend()	Returns a reverse iterator to the end

Search

Operation	Description
find()	Find characters in the string
rfind()	Find the last occurrence of a substring
find_first_of()	Find first occurrence of characters
find_first_not_of	Find first absence of characters
find_last_of	Find last occurrence of characters
find_last_not_of	Find last absence of characters

Numeric conversions

Operation	Description
stoi(), stol(), stoll()	Converts a string to an signed integer
stoul(), stoull()	Converts a string to an unsigned integer
stof(), stod(), stold()	Converts a string to an floating point value
to_string()	Converts an integral or floating point value to string
to_wstring()	Converts an integral or floating point value to wstring

References:

http://msdn.microsoft.com/en-us/
Nicolai M. Josuttis: "The C++ Standard Library"

Example:

Example - I/O string

Problem

This simple program shows how to read and how to print out a string.

Workings

#include <iostream>
#include <string>
 
using namespace std;
 
int main()
{
    // Enter text into a string
    string qWord;
    cout << "Enter a word: ";
    cin >> qWord;
    cout << "The word is: " << qWord << endl;
 
    return 0;
}

Solution

Output:

Enter a word: Hello!
The word is: Hello!

References:

http://xoax.net/