判断字符型变量c1是否为数字字符的正确表达式为
A、'0'<=c1<='9';
B、('9'>=c1)&&('0'<=c1);
C、(c1<='9')||(c1>='0');
D、(c1>='9')&&(c1<='0')
发布时间:2024-09-29 14:47:37
A、'0'<=c1<='9';
B、('9'>=c1)&&('0'<=c1);
C、(c1<='9')||(c1>='0');
D、(c1>='9')&&(c1<='0')