C库函数 - islower() C库函数 - isgraph() C库函数 - isprint() C库函数 - islower() #include <stdio.h> #include <ctype.h> int main () { int var1 = 'Q'; int var2 = 'q'; int var3 = '3'; if( islower(var1) ) { printf("var1 = |%c| is lowercase character\n", var1 ); } else { printf("var1 = |%c| is not lowercase character\n", var1 ); } if( islower(var2) ) { printf("var2 = |%c| is lowercase character\n", var2 ); } else { printf("var2 = |%c| is not lowercase character\n", var2 ); } if( islower(var3) ) { printf("var3 = |%c| is lowercase character\n", var3 ); } else { printf("var3 = |%c| is not lowercase character\n", var3 ); } return(0); } C库函数 - isgraph() C库函数 - isprint()