String类的常用方法

    public class StringAPIDemo12{51Testing软件测试网b+w H ^Z6T;[;Kc/T

        public static void main(String args[]){51Testing软件测试网b'a#j1pE)mycRZ0H!f

            String str1 = "hello" ; //声明字符串

            String newStr = str1.replaceAll("l","x") ; //现在将所有的“l”替换成x

            System.out.println("hello现在显示为" + newStr) ;

        }    

    } ;

public class StringAPIDemo04{51Testing软件测试网g9o;?3T*a*W

        public static void main(String args[]){51Testing软件测试网1HG0qW AP'o3Gp

            String str1 = "hello luoriver" ; //定义String对象

            int n = str1.length() ;

            System.out.println(n) ;  //将部分的byte数组变为字符串

        }

    } ;51Testing软件测试网V9e-Ten

   public class StringAPIDemo05{

        public static void main(String args[]){51Testing软件测试网6hb*HV5~FH%k;R7X~

            String str1 = "abcdefgcgh" ; //声明字符串

            System.out.println(str1.indexOf("c")) ;  //查找返回位置51Testing软件测试网1g'_ g;Mb:n

            System.out.println(str1.indexOf("c",3)) ;  //查找返回位置，从第4个位置开始查找

        }51Testing软件测试网'i L*a6Hcvu%U

    } ;

   public class StringAPIDemo05{51Testing软件测试网*nzzm{_xs!\

        public static void main(String args[]){51Testing软件测试网Ig~@H2GG Y

            String str1 = "abcdefgcgh" ; //声明字符串

            System.out.println(str1.indexOf("c")) ;  //查找返回位置51Testing软件测试网Y5@n0ZS,r9b*TxnS

            System.out.println(str1.indexOf("c",3)) ;  //查找返回位置，从第4个位置开始查找51Testing软件测试网 G]:U6C3fE4Z

            System.out.println(str1.indexOf("x")) ;  //没有查找到返回-1           51Testing软件测试网s.avQN+Bn

        }

    } ;

251Testing软件测试网$`s7zOp(?Ej q

751Testing软件测试网mM'xOH5X"s

-151Testing软件测试网 O%rs4g_7Q k;Z

    public class StringAPIDemo11{51Testing软件测试网2P2N"p#Wh6{'C6dP,O

        public static void main(String args[]){

            String str1 = "helloWORLD" ; //声明字符串51Testing软件测试网*^4@k.c#s0Du

            String str2 = "HELLOworld" ; //声明字符串51Testing软件测试网)UI)\3p8C \

          51Testing软件测试网^R$d7QIC"I a(d'l

                System.out.println("\"helloWORLD\" equalsIgnoreCase \"helloworld\" " + str1.equalsIgnoreCase(str2)) ;           51Testing软件测试网4B/d6]bj2N7Q/^v2\

                System.out.println("\"helloWORLD\" equals \"helloworld\" " + str1.equals(str2)) ;

        }    51Testing软件测试网;HQ@E3j3~(nD

    } ;

Subtopic

  public class StringAPIDemo10{51Testing软件测试网~TKCF"c4E7_

        public static void main(String args[]){

            String str1 = "**hello" ; //声明字符串51Testing软件测试网f
@wN_6t&w

            String str2 = "hello**" ; //声明字符串

            if(str1.startsWith("**")){//判断是否以"**"开头51Testing软件测试网/URa#d;l9`$z

                System.out.println("(**HELLO)以**开头") ;51Testing软件测试网;\Bp`3v.cigWtk

            }

            if(str2.endsWith("**")){//判断是否以"**"结尾51Testing软件测试网Gi5Hz;X3dd"U,Z
K8\

                System.out.println("(**HELLO)以**结尾") ;51Testing软件测试网Ys~(V6J

            }

            }

    } ;51Testing软件测试网kHkZ S#Na(enq

(**HELLO)以**开头

(**HELLO)以**结尾

    public class StringAPIDemo09{

        public static void main(String args[]){

            String str1 = "hello,luoriver" ; //声明字符串51Testing软件测试网4wb
ue? {\

            System.out.println("将\"hello world\"转换成大写：" + str1.toUpperCase()) ;

            System.out.println("将\"HELLO WORLD\"转换成小写：" + str1.toLowerCase()) ;

            }

    } ;

将"hello world"转换成大写：HELLO,LUORIVER

将"HELLO WORLD"转换成小写：hello,luoriver

    public class StringAPIDemo07{51Testing软件测试网A
G/zn^u

        public static void main(String args[]){

            String str1 = "hello,luoriver" ; //声明字符串

            System.out.println(str1.substring(2)) ;  //查找返回位置

            System.out.println(str1.substring(3,7)) ;

            System.out.println(str1.substring(22)) ;

        }

    } ;

llo,luoriver

lo,l

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String ind51Testing软件测试网T9l,hPW~;r

ex out of range: -851Testing软件测试网!mtM\3j.H$n

        at java.lang.String.substring(Unknown Source)

        at StringAPIDemo07.main(StringAPIDemo07.java:6)51Testing软件测试网:a(x N&nXl7F
A

    public class StringAPIDemo06{

        public static void main(String args[]){51Testing软件测试网+~J W8J7|xy$S

            String str1 = "    hello,luoriver   " ; //声明字符串51Testing软件测试网s#L2t jUrmy

            System.out.println(str1) ;  //查找返回左右位置

            System.out.println(str1.trim()) ;  //去掉空格

        }

    } ;51Testing软件测试网7vxlsKLS

    hello,luoriver

hello,luoriver51Testing软件测试网P;h5b5PHbKzQ

    public class StringAPIDemo03{51Testing软件测试网@ eKEFCf"I#k

        public static void main(String args[]){51Testing软件测试网E-e!}@)T

            String str1 = "hello" ; //定义String对象51Testing软件测试网] [uFz

            byte b[] = str1.getBytes() ; //将字符串变为byte51Testing软件测试网2RY i^?[ V#x

            System.out.println(new String(b)) ;  //将全部的byte数组变为字符串 

            System.out.println(new String(b,1,3)) ;  //将部分的byte数组变为字符串

        }51Testing软件测试网 aMNvz

    } ;

hello

ell51Testing软件测试网XX l2H
e$W8r}EKa

    public class StringAPIDemo02{

        public static void main(String args[]){

            String str1 = "hello" ; //定义String对象51Testing软件测试网 Z1Fc@3}#|+h;[V

            System.out.println(str1.charAt(3)) ;  //取出字符串中第四个字符     51Testing软件测试网%UC8E}M^

        }51Testing软件测试网1v$[|dch"xK

    }51Testing软件测试网D!D{Y OBx'W

    public class StringAPIDemo01{

        public static void main(String args[]){51Testing软件测试网Bo$D'x5Xs

            String str1 = "hello" ; //字义字符串

            char c[] = str1.toCharArray() ; //将一个字符串变为一个数组

           51Testing软件测试网8A A6\/Ra#H)v"_

            for(int i=0; i<c.length;i++){  //循环输出

                System.out.print(c[i] + "、") ;  

            }51Testing软件测试网qQP1c6NE

        }51Testing软件测试网4F
@4HQ2Vq

    }51Testing软件测试网
k#Vw {*[G_k;o

    public class StringAPIDemo01{51Testing软件测试网t/G:Zt5{

        public static void main(String args[]){51Testing软件测试网 h!qN8]p

            String str1 = "hello" ; //字义字符串51Testing软件测试网J e'DI"tP:@1^O

            char c[] = str1.toCharArray() ; //将一个字符串变为一个数组51Testing软件测试网]dPy+z] NZ$m%_

            for(int i=0; i<c.length;i++){  //循环输出

                 System.out.print(c[i] + "、") ;

                }51Testing软件测试网$};otVBqb)v

            System.out.println("") ;        //换行

            String str2 = new String(c) ;   //将全部的字符数组变为String

            String str3 = new String(c,0,3) ; //将部分字符数组变为为字符串

           51Testing软件测试网QK)Y(LK$S

            System.out.println(str2) ;      //输出字符串               51Testing软件测试网7D*aA(T ]
C}y@

            System.out.println(str3) ;     //输出字符串51Testing软件测试网'q,S{'[ul

        }

    }51Testing软件测试网R%v _Cu3_

    public class StringAPIDemo01{

        public static void main(String args[]){51Testing软件测试网Z9dt&D3h^ oe

            String str1 = "hello" ; //字义字符串

            char c[] = str1.toCharArray() ; //将一个字符串变为一个数组

            for(int i=0; i<c.length;i++){  //循环输出51Testing软件测试网!vE:@P$v/c

                 System.out.print(c[i] + "、") ;51Testing软件测试网qHo-xZ!I;l

               51Testing软件测试网w3GFN?\*Y1y F

                }

               51Testing软件测试网
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gb

            System.out.println("") ;        //换行51Testing软件测试网(h e6\t,XT_

            String str2 = new String(c) ;   //将全部的字符数组变为String

            String str3 = new String(c,0,3) ; //将部分字符数组变为为字符串51Testing软件测试网s+`,JwZ0W9e

            System.out.println(str2) ;      //输出字符串               51Testing软件测试网*dx"B N STN'wUr

            System.out.println(str3) ;     //输出字符串

        }51Testing软件测试网,MK$ODce;u

    }