c＃ - {string [0]}是什么意思？

Question

Setup:

Having a dumb day.

I have the following code:

UserRoles = Roles.GetRolesForUser(username);

Problem:

If username is an empty string ("", user not logged in), then when I check the value of UserRoles in the immediate window it shows:

{string[0]}

Question:

What is {string[0]} ?

How can I replicate this value to test my code for the case of an unlogged in user (username == "")?

NOTE: I have googled for this but to no avail.

Answer 1

GetRolesForUser返回一个角色数组，因此立即窗口中的“String [0]”只意味着它知道返回类型是一个数组（在本例中为字符串），但是没有条目（因为没有返回任何角色）空白用户。

Answer 2

It's an empty array of strings. You can create an empty string array like

string[] emptyArray = new string[0];

Answer 3

If you look at the documentation of Roles.GetRolesForUser(string) you will see that it returns an array of strings: string[]

{string[0]} means that you have an array with zero elements.

Answer 4

It is how the immediate window shows an empty array of strings:

[Test]
public void StringsTest()
{
    var strings = new string[] {};
}

In your test code you could Mock IRoles and have GetRolesForUser(username) return new string[] {}

Answer 5

它表示该值是一个包含0个元素的字符串数组