java中:
String
str =
"1111111";
if(isNumeric(
str)){
System.out.println(
"是");
}
else{
System.out.println(
"不是");
}
public static boolean isNumeric(String
str){
for (
int i =
0; i <
str.length(); i++){
System.out.println(
str.charAt(i));
if (!Character.isDigit(
str.charAt(i))){
return false;
}
}
return true;
}
js中:
var code = $(
"#code").val();
if(
isNaN(code)){
alert(
"不是数字")
}
else{
alert(
"是数字");
}
<input type=
"text" name=
"code" id=
"code" placeholder=
"输入小于五位的数字">
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