`strlib.h`

This file exports several useful string functions that are not included in the C++ string library.

Functions
boolToString(`b`)	Converts a boolean value into the corresponding string form.
charToString(`c`)	Converts a character value into the corresponding string form.
endsWith(`str`, `suffix`)	Returns `true` if the string `str` ends with the specified suffix, which may be either a string or a character.
equalsIgnoreCase(`s1`, `s2`)	Returns `true` if `s1` and `s2` are equal discounting differences in case.
integerToString(`n`)	Converts an integer into the corresponding string of digits.
realToString(`d`)	Converts a floating-point number into the corresponding string form.
startsWith(`str`, `prefix`)	Returns `true` if the string `str` starts with the specified prefix, which may be either a string or a character.
stringContains(`str`, `substr`)	Returns whether the given substring can be found in the given string.
stringIndexOf(`str`, `substr`)	Returns the index of the start of the first occurrence of the given substring in the given string.
stringIsInteger(`str`) stringIsInteger(`str`, `radix`)	Returns whether the given string can be successfully converted into an integer.
stringIsReal(`str`)	Returns whether the given string can be successfully converted into a real number.
stringJoin(`v`, `delimiter`)	Concatenates the given vector of strings into a single string using the given separator.
stringLastIndexOf(`str`, `substr`)	Returns the index of the start of the last occurrence of the given substring in the given string.
stringReplace(`str`, `old`, `new`)	Returns a new string with all occurrences of `old` changed into `new`.
stringSplit(`str`, `delimiter`)	Breaks apart the given string using the given separator.
stringToBool(`str`)	Converts a string representing a boolean value into its corresponding value.
stringToChar(`str`)	Converts a single-character string into its corresponding char value.
stringToInteger(`str`) stringToInteger(`str`, `radix`)	Converts a string of digits into an integer.
stringToReal(`str`)	Converts a string representing a real number into its corresponding value.
toLowerCase(`str`)	Returns a new string in which all uppercase characters have been converted into their lowercase equivalents.
toUpperCase(`str`)	Returns a new string in which all lowercase characters have been converted into their uppercase equivalents.
trim(`str`)	Returns a new string after removing any whitespace characters from the beginning and end of the argument.
trimEnd(`str`)	Returns a new string after removing any whitespace characters from the end of the argument.
trimStart(`str`)	Returns a new string after removing any whitespace characters from the beginning of the argument.
urlDecode(`str`)	Returns a URL-decoded version of the given string.
urlEncode(`str`)	Returns a URL-encoded version of the given string.

Function detail

string integerToString(int n);

Converts an integer into the corresponding string of digits. For example, calling integerToString(123) returns the string "123".

Usage:

string s = integerToString(n);

int stringToInteger(string str);
int stringToInteger(string str, int radix);

Converts a string of digits into an integer. If the string is not a legal integer or contains extraneous characters other than whitespace, stringToInteger calls error with an appropriate message. The function accepts an optional radix (base); for example, stringToInteger("234", 16) assumes that the string is in base-16 and returns 2*16*16 + 3*16 + 4 = 564.

Usage:

int n = stringToInteger(str);
int n2 = stringToInteger(str, radix);

Second version of this function (with radix parameter) available since: 2015/04/26 version of C++ library

bool stringIsInteger(string str);
bool stringIsInteger(string str, int radix);

Returns true if the given string can be successfully converted into an integer; that is, if it consists of digits and an optional +/- sign at the front. It can be useful to call this function before calling stringToInteger to make sure that the conversion will not fail. Optionally accepts a radix (base) parameter if base-10 is not desired.

Usage:

if (stringIsInteger(str)) { ...

Available since: 2014/02/01 version of C++ library

Second version of this function (with radix parameter) available since: 2015/04/26 version of C++ library

bool stringIsReal(string str);

Returns true if the given string can be successfully converted into a real number; that is, if it consists of digits, an optional decimal point, an optional +/- sign at the front, and so on. It can be useful to call this function before calling stringToReal to make sure that the conversion will not fail.

Usage:

if (stringIsReal(str)) { ...

Available since: 2014/02/01 version of C++ library

string realToString(double d);

Converts a floating-point number into the corresponding string form. For example, calling realToString(23.45) returns the string "23.45".

Usage:

string s = realToString(d);

double stringToReal(string str);

Converts a string representing a real number into its corresponding value. If the string is not a legal floating-point number or contains extraneous characters other than whitespace, stringToReal calls error with an appropriate message.

Usage:

double d = stringToReal(str);

string boolToString(bool b);

Converts a boolean value into the corresponding string form. For example, calling boolToString(true) returns the string "true".

Usage:

string s = boolToString(b);

Available since: 2014/02/01 version of C++ library

bool stringToBool(string str);

Converts a string representing a boolean value into its corresponding value. The only values recognized are the string literals "true" or "false". If the string is not "true" or "false" or contains extraneous characters other than whitespace, stringToBool calls error with an appropriate message.

Usage:

bool b = stringToBool(str);

Available since: 2014/02/01 version of C++ library

string charToString(char c);

Converts a character into the corresponding string form. For example, calling charToString('Q') returns the string "Q".

Usage:

string s = charToString(c);

Available since: 2014/02/01 version of C++ library

char stringToChar(string str);

Converts a single-character string into its corresponding char value. Typically you can just write str[0] to access the first character of a string; this function is merely provided for consistency with the other type-conversion functions. If the string is not exactly 1 character in length or contains extraneous characters other than whitespace, stringTochar calls error with an appropriate message.

Usage:

char c = stringToChar(str);

Available since: 2014/02/01 version of C++ library

bool stringContains(string str, string substr);

Returns true if the given substring can be found within the given string.

Usage:

if (stringContains(str, substr)) { ...

Available since: 2014/02/01 version of C++ library

string stringReplace(string str, string old, string replacement);

Returns a new string that is the same as str but with all occurrences of old changed into replacement.

Usage:

string s = stringReplace(s, "foo", "bar");

Available since: 2014/02/01 version of C++ library

string toUpperCase(string str);

Returns a new string in which all lowercase characters have been converted into their uppercase equivalents.

Usage:

string s = toUpperCase(str);

string toLowerCase(string str);

Returns a new string in which all uppercase characters have been converted into their lowercase equivalents.

Usage:

string s = toLowerCase(str);

bool equalsIgnoreCase(string s1, string s2);

Returns true if s1 and s2 are equal discounting differences in case.

Usage:

if (equalsIgnoreCase(s1, s2)) ...

bool startsWith(string str, string prefix);
bool startsWith(string str, char prefix);

Returns true if the string str starts with the specified prefix, which may be either a string or a character.

Usage:

if (startsWith(str, prefix)) ...

bool endsWith(string str, string suffix);
bool endsWith(string str, char suffix);

Returns true if the string str ends with the specified suffix, which may be either a string or a character.

Usage:

if (endsWith(str, suffix)) ...

string trim(string str);

Returns a new string after removing any whitespace characters from the beginning and end of the argument.

Usage:

string trimmed = trim(str);

string trimEnd(string str);

Returns a new string after removing any whitespace characters from the end of the argument.

Usage:

string trimmed = trimEnd(str);

string trimStart(string str);

Returns a new string after removing any whitespace characters from the beginning of the argument.

Usage:

string trimmed = trimStart(str);

int stringIndexOf(string s, string substring);

Returns the index of the start of the first occurrence of the given substring in s, if it occurs in s. If it does not occur, returns -1. This function is very similar to string.find, but find returns string::npos when the string is not found.

Usage:

int index = stringIndexOf(s, sub);

Available since: 2014/02/01 version of C++ library

int stringLastIndexOf(string s, string substring);

Returns the index of the start of the last occurrence of the given substring in s, if it occurs in s. If it does not occur, returns -1. This function is very similar to string.rfind, but find returns string::npos when the string is not found.

Usage:

int index = stringLastIndexOf(s, sub);

Available since: 2014/02/01 version of C++ library

vector<string> stringSplit(string str, string delimiter);

Returns an STL vector whose elements are strings formed by splitting the given string by the given separator. For example, splitting "Hi there Jim!" on " " returns {"Hi", "there", "", "Jim!"}.

Usage:

vector<string> v = stringSplit(str, delimiter);

Available since: 2014/02/01 version of C++ library

string stringJoin(const vector<string>& v, string delimiter = "\n");

Combines the elements of the given STL vector into a single string, with the given delimiter separating neighboring elements, and returns it. For example, joining the elements of the vector {"Hi", "there", "", "Jim"} with the delimiter "?" returns "Hi?there??Jim".

Usage:

string s = stringJoin(v, delimiter);

Available since: 2014/02/01 version of C++ library

string urlDecode(string value);

Returns a URL-decoded version of the given string, where any %xx character codes are converted back to the equivalent characters.

Usage:

string s = urlDecode(value);

Available since: 2014/02/01 version of C++ library

string urlEncode(string value);

Returns a URL-encoded version of the given string, where most non- alphabetic characters are replaced by %xx character codes.

Usage:

string s = urlEncode(value);

Available since: 2014/02/01 version of C++ library