分析下面的三行代码,创建了几个对象? ( )String s = new String("abc");String s1 = "abc";String s2 = new String("abc");
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执行完2题的三行代码后,接着执行下面的三行代码, 输出的结果是:( )System.out.println(s == s1);System.out.println(s == s2);System.out.println(s1 == s2);
A. true true true
B. false false true
C. false fasle false
D. true true false
下面代码段输出的结果是( )String str = "hello word";String substr=str.substring(0,3);System.out.println(substr);
A. null
B. hell
C. ell
D. hel
下面的程序段输出的结果是( )String s1="Abc",s2="Bcd";System.out.println(s1.compareTo(s2));
A. -1
B. 1
C. true
D. false
下面代码段输出的结果是( )StringBuffer sb = new StringBuffer("huangjianfeng");sb.delete(1,3);System.out.println(sb.toString());
A. ngjianfeng
B. hgjianfeng
C. hngjianfeng
D. hjianfeng