97 lines
3.3 KiB
C#
97 lines
3.3 KiB
C#
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namespace Lesson23_面向对象相关_String
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{
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internal class Program
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{
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static void Main(string[] args)
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{
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#region 知识点一 字符串指定位置获取
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//string是一个密封类，不能被继承
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//字符串的本质是一个char数组
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string str = "123";
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Console.WriteLine(str[0]);//一个类能通过中括号访问，那么这个类就实现了索引器
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//转换为char数组
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char[] chars = str.ToCharArray();
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Console.WriteLine(chars[1]);
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for (int i = 0; i < chars.Length; i++)
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{
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Console.Write(chars[i]);
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}
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Console.WriteLine();
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#endregion
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#region 知识点二 字符串拼接
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str = string.Format("{0},{1}", 1, 2);
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Console.WriteLine(str);
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str = "123" + "456";
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Console.WriteLine(str);
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Console.WriteLine();
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#endregion
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#region 知识点三 正向查找字符位置
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str = "abcdefg";
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int index = str.IndexOf("b");
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Console.WriteLine(index);
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index = str.IndexOf("noindex");
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Console.WriteLine(index);//找不到返回-1
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#endregion
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#region 知识点四 反向查找指定字符串位置
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str = "123321";
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index = str.IndexOf("2");//正向查找第一个2
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Console.WriteLine(index);
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index = str.LastIndexOf("2");
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Console.WriteLine(index);//反向查找第一个2
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Console.WriteLine();
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#endregion
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#region 知识点五 移除指定位置后的字符
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str = "1234567890";
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Console.WriteLine(str);
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str = str.Remove(5);//移除指定位置后的字符
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Console.WriteLine(str);
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str = str.Remove(1, 3);//从指定位置开始移除指定个数的字符
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//从第1个位置往后移除3个字符
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Console.WriteLine(str);
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Console.WriteLine();
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#endregion
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#region 知识点六 替换指定字符串
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str = "abcdefg";
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str = str.Replace("cd", "CD");
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Console.WriteLine(str);
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Console.WriteLine();
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#endregion
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#region 知识点七 大小写转换
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str = "abcDEF";
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str = str.ToUpper();
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Console.WriteLine(str);
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str = str.ToLower();
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Console.WriteLine(str);
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Console.WriteLine();
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#endregion
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#region 知识点八 字符串截取
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str = "1234567890";
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str = str.Substring(3);//从指定位置开始截取到字符串末尾
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Console.WriteLine(str);
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str = "1234567890";
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str = str.Substring(3,5);//从指定位置开始截取指定个数的字符
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Console.WriteLine(str);
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#endregion
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#region 知识点九 字符串分割
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str = "1,2,3,4,5,6";
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string[] strArray = str.Split(',');//根据指定字符分割字符串，返回字符串数组
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foreach (var item in strArray)
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{
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Console.WriteLine(item);
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}
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#endregion
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}
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}
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}
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