[lang-ref] ( is_alpha ) ( csharp )

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

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


    Assert.Equal(expected, actual);
}