namespace std {
int isalnum(int ch);
}
概要
ch が英数字かどうかを判定する（判定はロケールの影響を受ける）。
戻り値
ch が英数字と判定されれば非ゼロを、そうでなければゼロを返す。
例
#include <cctype>
#include <iostream>
int main() {
std::cout << "isalnum('A') = " << std::isalnum('A') << std::endl
<< "isalnum('a') = " << std::isalnum('a') << std::endl
<< "isalnum('Z') = " << std::isalnum('Z') << std::endl
<< "isalnum('z') = " << std::isalnum('z') << std::endl
<< "isalnum('3') = " << std::isalnum('3') << std::endl
<< "isalnum('.') = " << std::isalnum('.') << std::endl
<< "isalnum(' ') = " << std::isalnum(' ') << std::endl
<< "isalnum('\\n') = " << std::isalnum('\n') << std::endl
<< "isalnum('0x0f') = " << std::isalnum(15) << std::endl;
}
xxxxxxxxxx#include <cctype>#include <iostream>int main() { std::cout << "isalnum('A') = " << std::isalnum('A') << std::endl << "isalnum('a') = " << std::isalnum('a') << std::endl << "isalnum('Z') = " << std::isalnum('Z') << std::endl << "isalnum('z') = " << std::isalnum('z') << std::endl << "isalnum('3') = " << std::isalnum('3') << std::endl << "isalnum('.') = " << std::isalnum('.') << std::endl << "isalnum(' ') = " << std::isalnum(' ') << std::endl << "isalnum('\\n') = " << std::isalnum('\n') << std::endl << "isalnum('0x0f') = " << std::isalnum(15) << std::endl;}出力例
isalnum('A') = 8
isalnum('a') = 8
isalnum('Z') = 8
isalnum('z') = 8
isalnum('3') = 8
isalnum('.') = 0
isalnum(' ') = 0
isalnum('\n') = 0
isalnum('0x0f') = 0