1用JAVA自帶的函數(shù)
public?static?boolean?isNumeric(String?str){
??for?(int?i?=?str.length();--i>=0;){???
???if?(!Character.isDigit(str.charAt(i))){
????return?false;
???}
??}
??return?true;
?}
2用正則表達(dá)式
public static boolean isNumeric(String str){
??? Pattern pattern = Pattern.compile("[0-9]*");
??? return pattern.matcher(str).matches();???
?}
3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;
}