下面的哪些程序片断可能导致错误?( )
A: String s=”Hello”; String t=,,World"; String k=s+t;
B: String s=,,Hello";String t;t=s[3]+"one";
C: String s="Hello,,;String standard = s.tollpperCase();
D: String s="Hello World”;String t=s-”World”;
A: String s=”Hello”; String t=,,World"; String k=s+t;
B: String s=,,Hello";String t;t=s[3]+"one";
C: String s="Hello,,;String standard = s.tollpperCase();
D: String s="Hello World”;String t=s-”World”;
举一反三
- 下面的哪些程序片断可能导致错误() A: String s = "Gone with the wind"; String t = " good "; String k = s + t; B: String s = "Gone with the wind"; String t; t = s[3] + "one"; C: String s = "Gone with the wind"; String standard = s.toUpperCase(); D: String s = "home directory"; String t = s - "directory"
- 下面的哪些程序片断可能导致错误?( )。 A: String s="Gone with the wind";String t;t=s[3]+"one"; B: String s="Gone with the wind";String t="good";String k=s+t; C: String s="Gone with the wind";String standard=s.toUpperCase(); D: String s="home directory";String t=s-"directory";
- 以下要输出“hello,world!”正确的是? A: String s=String.format("%1s%2s","hello","world");System.out.println(s); B: String s=String.format("%1$s,%2$s","hello","world");System.out.println(s); C: String s=String.format("%s,%s","hello","world");System.out.println(s); D: String s=String.format("%1s,%2s","hello","world");System.out.println(s);
- 若String s = “Hello” ; String t = “Hello”;String c=new String(s);则下列哪个表达式返回false?( ) A: s.equals(t); B: t.equals(c); C: s==c; D: s==t;
- 下列代码片段执行结果是:String s=new String(”abc”); String s1=new String(s); if(s==s1){ System.out.println(”Hello”); } if(s.equals(s1)){ System.out.println(”World”); } A: Hello World B: Hello C: World D: Null