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public class StringTest2
{
public static void main(String[] args)
{
String s = "abcdefabc";
System.out.println("字符a第一次出现的位置为+"+s.indexOf('a')); //索引第一个出现的字符
System.out.println("zifuchuan bc di yici chuxiande weizhi wei"+s.indexOf("bc"));//找第一个字符串出现的地址
System.out.println("zifua zuihouchuxiande weizhi wei"+s.lastIndexOf('a')); //找最后一个字符出现的地址
System.out.println("congweizhi3kaishidaojieshudezifuchuan"+s.substring(3));//从第三个字符(不包括第3个)开始到最后一个字符的字符串。
System.out.println("congweizhi3kaishidao6zhijiandezifuchuan"+s.substring(3,6));//从第4个字符到第6个字符的字符串
}
}
结果:
字符a第一次出现的位置为+0
zifuchuan bc di yici chuxiande weizhi wei1
zifua zuihouchuxiande weizhi wei6
congweizhi3kaishidaojieshudezifuchuan defabc
congweizhi3kaishidao6zhijiandezifuchuan def
public class StringBuilderTest{
public static void main(String[] args)
{
StringBuilder s1 = new StringBuilder();
s1.append("java");
StringBuilder s2 = new StringBuilder(5);
StringBuilder s3 = new StringBuilder("shiyanlou");
System.out.println("///////////////////////");
System.out.println(s1);
System.out.println("s1:"+s1.toString()+"\tcap:"+s1.capacity());
System.out.println("///////////////////////");
System.out.println(s2);
System.out.println("s2:"+s2.toString()+"\tcap:"+s2.capacity());
System.out.println("///////////////////////");
System.out.println(s3);
System.out.println("s3:"+s3.toString()+"\tcap"+s3.capacity());
}
}