吴裕雄--天生自然 JAVA开发学习：String 类

public class StringDemo{
   public static void main(String args[]){
      char[] helloArray = { 'r', 'u', 'n', 'o', 'o', 'b'};
      String helloString = new String(helloArray);
      System.out.println( helloString );
   }
}

public class StringDemo {
    public static void main(String args[]) {
        String site = "www.runoob.com";
        int len = site.length();
        System.out.println( "菜鸟教程网址长度 : " + len );
   }
}

public class StringDemo {
    public static void main(String args[]) {
        String string1 = "菜鸟教程网址：";
        System.out.println("1、" + string1 + "www.runoob.com");
    }
}

System.out.printf("浮点型变量的值为 " +
                  "%f, 整型变量的值为 " +
                  " %d, 字符串变量的值为 " +
                  "is %s", floatVar, intVar, stringVar);

String fs;
fs = String.format("浮点型变量的值为 " +
                   "%f, 整型变量的值为 " +
                   " %d, 字符串变量的值为 " +
                   " %s", floatVar, intVar, stringVar);

public class Test {

    public static void main(String args[]) {
        String s = "www.runoob.com";
        char result = s.charAt(8);
        System.out.println(result);
    }
}

public class Test {

    public static void main(String args[]) {
        String str1 = "Strings";
        String str2 = "Strings";
        String str3 = "Strings123";

        int result = str1.compareTo( str2 );
        System.out.println(result);

        result = str2.compareTo( str3 );
        System.out.println(result);

        result = str3.compareTo( str1 );
        System.out.println(result);
    }
}

public class Test {

    public static void main(String args[]) {
        String str1 = "STRINGS";
        String str2 = "Strings";
        String str3 = "Strings123";

        int result = str1.compareToIgnoreCase( str2 );
        System.out.println(result);

        result = str2.compareToIgnoreCase( str3 );
        System.out.println(result);

        result = str3.compareToIgnoreCase( str1 );
        System.out.println(result);
    }
}

public class Test {
    public static void main(String args[]) {
        String s = "菜鸟教程：";
        s = s.concat("www.runoob.com");
        System.out.println(s);
    }
}

public class Test {
    public static void main(String args[]) {
        String str1 = "String1";
        String str2 = "String2";
        StringBuffer str3 = new StringBuffer( "String1");

        boolean  result = str1.contentEquals( str3 );
        System.out.println(result);

        result = str2.contentEquals( str3 );
        System.out.println(result);
    }
}

public class Test {
    public static void main(String args[]) {
        char[] Str1 = {'h', 'e', 'l', 'l', 'o', ' ', 'r', 'u', 'n', 'o', 'o', 'b'};
        String Str2 = "";

        Str2 = Str2.copyValueOf( Str1 );
        System.out.println("返回结果：" + Str2);

        Str2 = Str2.copyValueOf( Str1, 2, 6 );
        System.out.println("返回结果：" + Str2);
    }
}

public class Test {
    public static void main(String args[]) {
        String Str = new String("菜鸟教程：www.runoob.com");
        boolean retVal;

        retVal = Str.endsWith( "runoob" );
        System.out.println("返回值 = " + retVal );

        retVal = Str.endsWith( "com" );
        System.out.println("返回值 = " + retVal );
    }

public class Test {
    public static void main(String args[]) {
        String Str1 = new String("runoob");
        String Str2 = Str1;
        String Str3 = new String("runoob");
        boolean retVal;

        retVal = Str1.equals( Str2 );
        System.out.println("返回值 = " + retVal );

        retVal = Str1.equals( Str3 );
        System.out.println("返回值 = " + retVal );
    }
}

public class Test {
    public static void main(String args[]) {
        String Str1 = new String("runoob");
        String Str2 = Str1;
        String Str3 = new String("runoob");
        String Str4 = new String("RUNOOB");
        boolean retVal;

        retVal = Str1.equals( Str2 );
        System.out.println("返回值 = " + retVal );

        retVal = Str3.equals( Str4);
        System.out.println("返回值 = " + retVal );

        retVal = Str1.equalsIgnoreCase( Str4 );
        System.out.println("返回值 = " + retVal );
    }
}

import java.io.*;

public class Test {
    public static void main(String args[]) {
        String Str1 = new String("runoob");

        try{
            byte[] Str2 = Str1.getBytes();
            System.out.println("返回值：" + Str2 );

            Str2 = Str1.getBytes( "UTF-8" );
            System.out.println("返回值：" + Str2 );

            Str2 = Str1.getBytes( "ISO-8859-1" );
            System.out.println("返回值：" + Str2 );
        } catch ( UnsupportedEncodingException e){
            System.out.println("不支持的字符集");
        }
    }
}

public class Test {
    public static void main(String args[]) {
        String Str1 = new String("www.runoob.com");
        char[] Str2 = new char[6];

        try {
            Str1.getChars(4, 10, Str2, 0);
            System.out.print("拷贝的字符串为：" );
            System.out.println(Str2 );
        } catch( Exception ex) {
            System.out.println("触发异常...");
        }
    }
}

public class Test {
    public static void main(String args[]) {
        String Str = new String("www.runoob.com");
        System.out.println("字符串的哈希码为 :" + Str.hashCode() );
    }
}

public class Main {
    public static void main(String args[]) {
        String string = "aaa456ac";
        //查找指定字符是在字符串中的下标。在则返回所在字符串下标；不在则返回-1.
        System.out.println(string.indexOf("b")); // indexOf(String str); 返回结果：-1，"b"不存在  

        // 从第四个字符位置开始往后继续查找，包含当前位置
        System.out.println(string.indexOf("a",3));//indexOf(String str, int fromIndex); 返回结果：6  

        //（与之前的差别：上面的参数是 String 类型，下面的参数是 int 类型）参考数据：a-97,b-98,c-99  

        // 从头开始查找是否存在指定的字符
        System.out.println(string.indexOf(99));//indexOf(int ch)；返回结果：7
        System.out.println(string.indexOf('c'));//indexOf(int ch)；返回结果：7  

        //从fromIndex查找ch，这个是字符型变量，不是字符串。字符a对应的数字就是97。
        System.out.println(string.indexOf(97,3));//indexOf(int ch, int fromIndex); 返回结果：6
        System.out.println(string.indexOf('a',3));//indexOf(int ch, int fromIndex); 返回结果：6
    }
}

public class Test {
    public static void main(String args[]) {
        String Str = new String("菜鸟教程:www.runoob.com");
        String SubStr1 = new String("runoob");
        String SubStr2 = new String("com");

        System.out.print("查找字符 o 第一次出现的位置 :" );
        System.out.println(Str.indexOf( 'o' ));
        System.out.print("从第14个位置查找字符 o 第一次出现的位置 :" );
        System.out.println(Str.indexOf( 'o', 14 ));
        System.out.print("子字符串 SubStr1 第一次出现的位置:" );
        System.out.println( Str.indexOf( SubStr1 ));
        System.out.print("从第十五个位置开始搜索子字符串 SubStr1 第一次出现的位置 :" );
        System.out.println( Str.indexOf( SubStr1, 15 ));
        System.out.print("子字符串 SubStr2 第一次出现的位置 :" );
        System.out.println(Str.indexOf( SubStr2 ));
    }
}