学用 ASP.Net 之 "字符串" (1): 基础

字符串连接:

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protected void Button1_Click(object sender, EventArgs e)
{
    string str1="abcd", str2="efg";
    str1 += str2;
    Response.Write(str1); //abcdefg
}

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从字符串中提取字符:

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protected void Button1_Click(object sender, EventArgs e)
{
    string str = "abcdefg";
    char c = str[1];   //read only  
    Response.Write(c); //b
    Response.Write(str[str.Length-1]); //g
}

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从字符串中遍历字符:

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protected void Button1_Click(object sender, EventArgs e)
{
    string str = "abcdefg";
    for (int i = 0; i < str.Length; i++)
    {
        Response.Write(str[i] + "<br/>");
    }
    foreach (char c in str)
    {
        Response.Write("<hr/>" + c);
    }
}

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从字符编码转义到字符:

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protected void Button1_Click(object sender, EventArgs e)
{
    string str = "\u4e07\u4e00";
    Response.Write(str); //万一
}

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判断两字符串是否相同:

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protected void Button1_Click(object sender, EventArgs e)
{
    string str1="abc", str2="ABC";
    Response.Write(str1 == str2); //False
    Response.Write("<br/>");
    Response.Write(str1 != str2); //True
}

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使用 @ 免转义:

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protected void Button1_Click(object sender, EventArgs e)
{
    string str;
    str = "c:\\temp\\test.txt";
    Response.Write(str);    //c:\temp\test.txt
    Response.Write("<br/>");

    str = @"c:\temp\test.txt";
    Response.Write(str);    //c:\temp\test.txt
    Response.Write("<br/>");

    str = "\"asp.net\"";
    Response.Write(str);    //"asp.net"
    Response.Write("<br/>");

    str = @"""asp.net""";
    Response.Write(str);    //"asp.net"
    Response.Write("<br/>");
}

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使用构造函数:

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protected void Button1_Click(object sender, EventArgs e)
{
    string str;
    char[] cs = { 'a', 'b', 'c', 'd', 'e', 'f' };
    str = new string(cs);
    Response.Write(str);    //abcdef
    Response.Write("<br/>");

    str = new string(cs, 2, 3);
    Response.Write(str);    //cde
    Response.Write("<br/>");

    str = new string('a', 7);
    Response.Write(str);    //aaaaaaa
    Response.Write("<br/>");
}

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