[lang-ref] ( is_digit ) ( csharp )

[Theory]
[InlineData("a", false)]
[InlineData("1", true)]
[InlineData(" ", false)]
[InlineData(")", false)]
[InlineData("1.5", false)]
public void TestIsDigit(string text, bool expected)
{
    // text.All(char.IsDigit)

    bool actual = text.All(char.IsDigit);


    Assert.Equal(expected, actual);
}