std::basic_string::find
Da cppreference.com.
<metanoindex/>
<tbody> </tbody> size_type find( const basic_string& str, size_type pos = 0 ) const; |
(1) | |
size_type find( const CharT* s, size_type pos, size_type count ) const; |
(2) | |
size_type find( const CharT* s, size_type pos = 0 ) const; |
(3) | |
size_type find( CharT ch, size_type pos = 0 ) const; |
(4) | |
Trova la prima sottostringa uguale alla sequenza di caratteri dato. Ricerca inizia
pos, vale a dire la sottostringa trovata non deve iniziare in una posizione che precede pos.Original:
Finds the first substring equal to the given character sequence. Search begins at
pos, i.e. the found substring must not begin in a position preceding pos.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
1)
Trova la prima sottostringa uguale a
str. Original:
Finds the first substring equal to
str. The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
2)
Trova la prima sottostringa uguali ai caratteri
count prima della stringa di caratteri puntata da s. s possono includere caratteri nulli.Original:
Finds the first substring equal to the first
count characters of the character string pointed to by s. s can include null characters.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
3)
Trova la prima sottostringa uguale alla stringa di caratteri puntata da
s. La lunghezza della stringa è determinata dal carattere null prima.Original:
Finds the first substring equal to the character string pointed to by
s. The length of the string is determined by the first null character.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
4)
Trova il
ch primo carattere.Original:
Finds the first character
ch.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Parametri
| str | - | stringa da ricercare
Original: string to search for The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| count | - | lunghezza della stringa da cercare
Original: length of substring to search for The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| s | - | puntatore a una stringa di caratteri per cercare i per
Original: pointer to a character string to seach for The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| ch | - | carattere da cercare
Original: character to search for The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Valore di ritorno
posizione del primo carattere della sottostringa trovato o
npos in mancanza di tale stringa viene trovata.Original:
position of the first character of the found substring or
npos if no such substring is found.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Esempio
#include <string>
#include <iostream>
void print(std::string::size_type n, std::string const &s)
{
if (n == std::string::npos) {
std::cout << "not found\n";
} else {
std::cout << "found: " << s.substr(n) << '\n';
}
}
int main()
{
std::string::size_type n;
std::string const s = "This is a string";
// search from beginning of string
n = s.find("is");
print(n, s);
// search from position 5
n = s.find("is", 5);
print(n, s);
// find a single character
n = s.find('a');
print(n, s);
// find a single character
n = s.find('q');
print(n, s);
}
Output:
found: is is a string
found: is a string
found: a string
not found