std::atoi, std::atol, std::atoll
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| definiert in Header <cstdlib>
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| int atoi( const char *str ); |
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| long atol( const char *str ) |
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| long long atoll( const char *str ); |
(seit C++11) | |
Interpretiert den Byte String
str als Integer-Wert.Original:
Interprets an integer value in a byte string pointed to by
str.The text has been machine-translated via Google Translate.
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Die Funktion verwirft alle Leerzeichen bis zum ersten Nicht-Whitespace-Zeichen. Dann werden solange Zeichen gelesen, solange sie eine gültige ganze Zahl darstellen. Die gelesenen Zeichen werden anschließend in einen Integer-Wert umgewandelt. Der gültige Integer-Wert besteht aus den folgenden Teilen:
Original:
Function discards any whitespace characters until first non-whitespace character is found. Then it takes as many characters as possible to form a valid integer number representation and converts them to integer value. The valid integer value consists of the following parts:
The text has been machine-translated via Google Translate.
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- (optional) Plus-oder MinuszeichenOriginal:(optional) plus or minus signThe text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions. - ZiffernOriginal:numeric digitsThe text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Inhaltsverzeichnis |
[Bearbeiten] Parameter
| str | - | Zeiger auf den umzuwandelnden null-terminierten Byte-String
Original: pointer to the null-terminated byte string to be interpreted The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
[Bearbeiten] Rückgabewert
Im Erfolgsfall der dem Inhalt von
str entsprechende Integer-Wert. Falls der konvertierte Wert außerhalb des Wertebereichs des entsprechenden Rückgabetyps liegt, ist der Rückgabewert undefiniert. Falls keine Umwandlung möglich ist, wird 0 zurückgegeben.Original:
Integer value corresponding to the contents of
str on success. If the converted value falls out of range of corresponding return type, the return value is undefined. If no conversion can be performed, 0 is returned.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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[Bearbeiten] Beispiel
#include <iostream> #include <cstdlib> int main() { const char *str1 = "42"; const char *str2 = "3.14159"; const char *str3 = "31337 with words"; const char *str4 = "words and 2"; int num1 = std::atoi(str1); int num2 = std::atoi(str2); int num3 = std::atoi(str3); int num4 = std::atoi(str4); std::cout << "std::atoi(\"" << str1 << "\") is " << num1 << '\n'; std::cout << "std::atoi(\"" << str2 << "\") is " << num2 << '\n'; std::cout << "std::atoi(\"" << str3 << "\") is " << num3 << '\n'; std::cout << "std::atoi(\"" << str4 << "\") is " << num4 << '\n'; }
Output:
std::atoi("42") is 42
std::atoi("3.14159") is 3
std::atoi("31337 with words") is 31337
std::atoi("words and 2") is 0[Bearbeiten] Siehe auch
| (C++11) (C++11) (C++11) |
wandelt einen String in eine Ganzzahl Original: converts a string to an signed integer The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktion) |
| wandelt ein Byte-String in einen ganzzahligen Wert Original: converts a byte string to an integer value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktion) | |
| wandelt ein Byte-String in einen vorzeichenlosen Integer-Wert Original: converts a byte string to an unsigned integer value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktion) | |
| C documentation for atoi, atol, atoll
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