public static boolean isNumeric(String str) {
for (int i = str.length(); --i >= 0;) {
if (!Character.isDigit(str.charAt(i))) {
return false;
}
}
return true;
}
2.正則表達式
public static boolean isNumeric(String str) {
Pattern pattern = Pattern.compile("[0-9]*");
return pattern.matcher(str).matches();
}
3.還是正則表達式public static boolean isNumeric(String str) {
if (str.matches("\\d*")) {
return true;
}
return false;
}
4.用ascii碼
public static boolean isNumeric(String str) {
for (int i = str.length(); --i >= 0;) {
int chr = str.charAt(i);
if (chr < 48 || chr > 57)
return false;
}
return true;
}
