什么是（""）之间的差异，（空） [英] What is the difference between ("") and (null)

问题描述

尝试设置验证我起初遇到了一些问题，检查是否一个文本框为空，我用

While trying to set Validations i initially encountered some problems with checking if a textbox is null, i tried using

    private void btnGo_Click(object sender, EventArgs e)
    {
        string name = textLogin.Text;
        if (name == null)
        {
             labelError.Visiblle = true;
             labelError.Text = "Field Cannot be Left Blank"
        }
    }

但它没有工作，直到我试过这种

but it didn't work, until i tried this

    private void btnGo_Click(object sender, EventArgs e)
    {
        string name = textLogin.Text;
        if (name == "")
        {
             labelError.Visiblle = true;
             labelError.Text = "Field Cannot be Left Blank"
        }
    }

我的问题是我想知道（空）之间的差值（），为什么空是不工作。

My question is i want to know the difference between ("") and (null) and why null wasn't working.

在此先感谢

推荐答案

同为 0 和空数组的区别;一切。他们是不同的值。 ，是一个空字符串，这是一个空白文本框会怎样为文本就是一切。 空没有价值，是不是一个空白文本框都有为文本。

The same as the difference between 0 and an empty array; everything. They’re different values. "" is an empty string, and that’s what a blank textbox holds as text is all. null is no value, and is not what a blank textbox has as Text.

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