轉(zhuǎn)自：http://blog.csdn.net/xdz78/article/details/53057304
關(guān)于isdigit函數(shù)isdigit函數(shù)只能判斷字符型是否是數(shù)字如下#include <iostream>#include <cstdio>using namespace std;int main() {    char c;//此時(shí)輸入的是整型數(shù)字    while (cin>>c) {        if (isdigit(c)) {            cout<<c<<"是數(shù)字"<<endl;        } else cout<<c<<"不是數(shù)字"<<endl;    }    return 0;}//程序輸出如下：/*11是數(shù)字22是數(shù)字33是數(shù)字aa不是數(shù)字bb不是數(shù)字cc不是數(shù)字*///識(shí)別正確//但是如果把char c 改成int c 則無(wú)法識(shí)別數(shù)字和字符的區(qū)別//更改后的錯(cuò)誤程序輸出如下：/*11不是數(shù)字22不是數(shù)字33不是數(shù)字aPRocess returned 0 (0x0)   execution time : 3.267 sPress any key to continue.*/