检查字符串是否仅包含数字

def is_numeric(s):
    return s.isnumeric()

s = "12345"
print(is_numeric(s))

function isNumeric(s) {
    return !isNaN(s) && s !== null && s !== "" && s !== false;
}

var s = "12345";
console.log(isNumeric(s));

public static boolean isNumeric(String s) {
    return s.matches("[0-9]+");
}

String s = "12345";
System.out.println(isNumeric(s));

public static bool IsNumeric(string s) {
    return s.All(char.IsDigit);
}

string s = "12345";
Console.WriteLine(IsNumeric(s));

function isNumeric($s) {
    return is_numeric($s);
}

$s = "12345";
echo isNumeric($s);