⚔疯狂输出⚔ 类中的String的用法

1.根据字符 获取字符在字符串中的位置

public static  void fun2(){//字符串就相当于字符串数组   所以直接声明一个字符串String string =  "zifuchuan";          int index =  string.indexof("c"); 根据一个一个字符查找下标   //indexof System.out。println(index);}

我们会基本的根据字符在字符串数组中找到一个字符
下面我们用在字符串数组中随机找一个字符

public static void fun1（）{Sting string  = "zifuchuan";int index = String.infdexof("u",4)//从第四位开始查找   //intdexofSystem.out.println(index);}

根据下标找元素

public static void fun（）{String sring ="zifuchuan";char number = sring.charAt(5);    //根据下表找元素    //charAt（）；System.out.println(number);}

根据索引获取字符串中的字符

public static void fun（）{String string  = "zifuchuan";boolean  as  =  string.contains("uc");  //根据索引获取字符串的字符    //contains（）；System.out.println("as");}

判断字符串前缀是否正确

public static void fun(){String string = "www.zifuchuan.com";boolean  as1 =  string.startsWith("www");    //判断前缀 是否正确  startsWith（）；System.out.println(as1);}

判断字符串后悔是否正确

public static  void fun(){String string  = "www.zifuchuan.com"；boolean as2 = string.endWith(com);     //判断后缀  是否正确  endWith （）；System.out.println(as2);}

字符串的替换

public static  void fun（）{String  string   = "zifuchuan"String as = string.replace ("fu","chuan"); //  替换 replace（）；System.out.println(as);}

字符串的切割分离

public static void fun（）{String string   = "zifuchuan";String [] as   = string.split(u);   // 切割分离 split（）；System.out.println(array.length);}

字符串的截取

public  static void fun（）{String string   = ”zifuchuan“;String   as  =  string.substring（4）；   //截取substring（）；System.out.println（as）；}

字符串范围截取

public static void fun（）{String string  =  "zifuchuan";String as = string.substring(2,5);   // 截取部分 Substring（ ，）；System.out.println(as);}

字符串转换大小写
字符串转大写

public static void fun（）{String string = "zifuchuan";String as  =  String.toUpperCase();  // 转大写  toUpperCaseSystem.out.println(as);}

字符串转小写

public static void fun（）{String string  = "zifuchuan";String as = String.toLowerCase();   //转小写  toLowerCaseSystem.out.println（as）;}

字符串比较大小

public static void fun（）{String string = "ZIFUchuan";String string1 = " zifuCHUAN";System.out。println（string.equalsIgnoreCase（string1））;  //字符串比较大小  忽略大小写 equalsIgnoreCase }

去除字符串前后的空格

public static void fun（）{String  string  = "    s s d    ";  String s = string.trim();                //只能去除 前面和后面的空格System.out.println(s);}

比较两个字符串的大小

String string = "ada";String string1 = "aaa";int  num  =  string.conperTo(string1);  //比较两个字符串的ASCII码的值 等于0时两个字符串的值相等System.out.println(num);

把字符数组转化成字符串

public staic void fun(){char[]array = new char[]{1,2,3,1,3};String string = new string(array);       System.out.println(string);}

把字符串转化成字符数组

public static void fun（）{String string  =  "s d f f g a";char[]charArray =string.CharArray();for(char c: charArray){System.out.println(c);}}