String num = "a1";
boolean isNum = false;
try{
int n = Integer.parseInt(num)
} catch(Exception e) {
isNum = true;
}
if(isNum) {
System.out.println("num is not a Number");
} else {
System.out.println("num is a Number");
}
boolean isNum = false;
try{
int n = Integer.parseInt(num)
} catch(Exception e) {
isNum = true;
}
if(isNum) {
System.out.println("num is not a Number");
} else {
System.out.println("num is a Number");
}
但是"0x1234",也会认为是的(它当然是,不过不知道你是否喜欢)