在字符串中找到一个词 [英] finding a word in a string

问题描述

大家好，

我正在制作另一种编程语言，而这种编程语言的不同之处在于您可以使用自己的名称来创建变量.我以前的代码，要设置一个变量，您将必须输入类似于以下内容的代码:

string1 =某物
打印字符串1

在我的新语言中，我想像这样编写代码:

#x:Hello World
print_var x

但是我要执行此操作的方式不是创建新变量，而是要查找变量名.我希望源代码看起来像这样:

hey guys,

i am making another programming language and the difference in this one is that you can make a variable with its own name. my previous ones, to set a variable, you would have to type a piece of code similar to:

string1 = something
print string1

in my new language, i want to make that code like this:

#x: Hello World
print_var x

but the way that i want to do this, is not making a new variable, i want to make it finding the variable name. i want the source code to look something like this:

for each a as string in textbox1.text.split(system.environment.newline())
     if a.contains("print_var ")
          variable = a.findstring(a.substring(10))
          textbox2.text = textbox2.text & vbcrlf & variable
     end if
next

could you please give me a piece of code that look similar to this ^ but can find the word?

推荐答案

以下代码可用于提取变量的值:来自TextBox1的Text .由于变量名称是使用a.SubString(10)
从Index 10获取的 最好使用a.StartsWith方法而不是a.contains方法.

The following code can be used to extract the value of variable from Text of TextBox1. Since, the variable name is taken from Index 10 using a.SubString(10)
it is better to use a.StartsWith method instead of a.contains method.

For Each a As String In TextBox1.Text.Split(ControlChars.Lf)
    If a.StartsWith("print_var ") Then
        TextBox2.Text &= vbCrLf + System.Text.RegularExpressions.Regex.Match( _
            TextBox1.Text, String.Format("(?<=#{0}: ).*", a.Substring(10)), _
            RegexOptions.CultureInvariant).Value
    End If
Next

(?<=#{0}: )模式与#x: 匹配，但将其从Match.Value中排除.

按此解决方案的注释中的要求添加了C#代码[/编辑]

请尝试以下代码:

The (?<=#{0}: ) pattern matches #x: , but excludes it from the Match.Value.

C# code added as sought in the comment to this solution [/Edit]

Please try the following code:

foreach (string a in TextBox1.Text.Split('\n')) {
    if (a.StartsWith("print_var ")) {
        TextBox2.Text += "\r\n" + System.Text.RegularExpressions.Regex.Match(TextBox1.Text, string.Format("(?<=#{0}: ).*", a.Substring(10)), RegexOptions.CultureInvariant).Value;
    }
}

如果要在TextBox2的开头避免使用enter (new line)，则将TextBox2.Text 初始化为String.Empty并有条件地引入vbCrLf ，如图所示在下面.

If the enter (new line) is to be avoided in the beginning of TextBox2, then initialize TextBox2.Text to String.Empty and introduce vbCrLf conditionally as shown below.

TextBox2.Text = String.Empty
For Each a As String In TextBox1.Text.Split(ControlChars.Lf)
    If a.StartsWith("print_var ") Then
        TextBox2.Text &= iif(String.IsNullOrEmpty(TextBox2.Text), _
            String.Empty, vbCrLf) & System.Text.RegularExpressions.Regex.Match( _
            TextBox1.Text, String.Format("(?<=#{0}: ).*", a.Substring(10)), _
            RegexOptions.CultureInvariant).Value
    End If
Next

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