C#對字符串常用操作(一)

一，字符串截取
1 string str3 = "123abc456";
2
3 //str3 = str3.Substring(0, i); //從左邊開始取字符串的前i個字符(str3 = str3.Remove(i, str3.Length - i)😉
4 str3 = str3.Substring(0, 3);
5 str3 = str3.Remove(3, str3.Length - 3);
6 //輸出："123"
7
8 //str3 = str3.Substring(i); //從左邊開始去掉字符串的前i個字符(str3=str3.Remove(0,i)😉
9 str3 = str3.Substring(3);
10 //輸出："abc456"11
12 //str3 = str3.Substring(str3.Length - i); //從右邊開始取i個字符(str3=str3.Remove(0,str3.Length-i))
13 str3 = str3.Substring(str3.Length - 3);
14 //輸出："456"
15
16 //str3 = str3.Substring(0, str3.Length - i); //從右邊開始去掉i個字符(str3=str3.Remove(str3.Length-i,i))
17 str3 = str3.Substring(0, str3.Length - 3);
18 //輸出："123abc"
二，字符串替換
1 string str6 = "123,abc,456,efg";
2 string[] str6s = str6.Split(',');
3 foreach (var item in str6s)
4 {
5 ConsoleStr(item);
6 }
7 //輸出："123 abc 789 efg"
三，字符串連接
1 string str8 = "abcdefgHIJK";
2 str8 = str8.ToUpper();
3 //輸出："ABCDEFGHIJK"
4
5 str8 = str8.ToLower();
6 //輸出："abcdefghijk"
7
8 bool isUpper = char.IsUpper(str8, 8);
9 //輸出："True"
四，字符串比較
1 string str10 = "abackhdk";
2
3 string str9 = "abac";
4 int aa = str9.CompareTo(str10);
5 //輸出："-1"
6
7 string str11 = "b";
8 int bb = str11.CompareTo(str10);
9 //輸出："1"
10
11 string str12 = "abackhdk";
12 int cc = str12.CompareTo(str10);
13 //輸出："0"
五，查找子串
1 str.IndexOf(子串，查找其實位置) ;
2 str.LastIndexOf(子串) ;最后一次出現的位置
3 str.IndexOf("ab",0);
六，插入子串
1 str.Insert(插入位置，插入子串) ;
2 s.Insert(2,"ab");
七，移出子串
1 str.Remove（其實位置，移出數）;
2 s.Remove(3,2);
八，去空格
1 string str = " I Believe You Very Much! ";
2 str = str.TrimStart(); //截取掉字符串首部的空格
3 //輸出："I Believe You Very Much! "
4
5 str = str.TrimStart('I'); //截取掉字符串第一個字符
6 //輸出："Believe You Very Much! "
7
8 str = str.TrimStart().TrimStart("Beli".ToCharArray()); //截取掉字符串首部及尾部出現的B或e或l或i字符,刪除的過程直到碰到一個既不是B也不是e也不是l也不是i的字符才結束。
9 //輸出："ve You Very Much! "
10
11 string str1 = " I Believe You Very Much! ";
12 str = str1.Trim(); //截取掉字符串首部和尾部的空格
13 //輸出："I Believe You Very Much!"
14
15 //TrimEnd的方法和TrimStart原理一樣不多贅述
16 string str2 = " I Believe You Very Much! ";
17 str = str2.TrimEnd(); //截取掉字符串首部和尾部的空格
18 //輸出：" I Believe You Very Much!"