public static void main(String[] args) {

String str = "Hello";

char[] chars = str.toCharArray();

System.out.println("字符串转字符数组：");

for (int i=0; i

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

}

System.out.println();

System.out.println("字符数组转字符串：");

String str1 = String.copyValueOf(chars);

System.out.println(str1);

System.out.println("字符串指定位置字符：");

System.out.println(str.charAt(1));

System.out.println("字符串转字节数组");

byte[] bytes = str.getBytes();

for (int i=0; i

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

}

System.out.println();

System.out.println("字节数组转字符串：");

System.out.println(new String(bytes));

System.out.println("大小写转换：");

System.out.println(str.toUpperCase());

System.out.println(str.toLowerCase());

System.out.println("字符串的比较：compareTo()");

/*

* compareTo()的返回值是整型,

* 它是先比较对应字符的大小(ASCII码顺序),

* 如果第一个字符和参数的第一个字符不等,

* 结束比较返回他们之间的差值,

* 如果第一个字符和参数的第一个字符相等,

* 则以第二个字符和参数的第二个字符做比较,

* 以此类推,直至比较的字符或被比较的字符有一方全比较完,这时就比较字符的长度.

* */

String s1 = "abc";

String s2 = "abcd";

String s3 = "abcdfg";

String s4 = "1bcdfg";

String s5 = "cdfg";

String s6 = "Abc";

System.out.println(s1.compareTo(s2)); // -1 (前面相等,s1长度小1)

System.out.println(s1.compareTo(s3)); // -3 (前面相等,s1长度小3)

System.out.println(s1.compareTo(s4)); // 48 ("a"的ASCII码是97,"1"的的ASCII码是49,所以返回48)

System.out.println(s1.compareTo(s5)); // -2 ("a"的ASCII码是97,"c"的ASCII码是99,所以返回-2)

System.out.println(s1.compareToIgnoreCase(s6)); // 0 忽略大小写

/*

* str1.equals(str2)比较内容

* str1==str2比较内存地址

* */

String s11 = new String("abc");

System.out.println(s1.equals(s11)); //true

System.out.println(s1==s11); //false

String s12 = "abc";

System.out.println(s1.equals(s12)); //true

System.out.println(s1==s12); //true

System.out.println("判断字符串前缀和后缀：");

System.out.println(str.startsWith("He")); //true

System.out.println(str.endsWith("ol")); //false

System.out.println("查找字符串：");

System.out.println(str.indexOf("e"));

System.out.println(str.indexOf('l'));

System.out.println(str.lastIndexOf('e'));

System.out.println("字符串截取：");

System.out.println(str.substring(1, 3));

System.out.println("字符串拆分：");

String s = "this is a string";

String strs[] = s.split(" "); //以空格拆分

for (int i=0; i

System.out.println(strs[i]);

}

}