UC知道Java英语试题.看看!!!
来源：百度知道 编辑：UC知道 时间：2024/05/17 21:11:06
2. Given the following declaration
String s = "Example";
Which are legal code?
A. s >>> = 3;
B. s[3] = "x";
C. int i = s.length();
D. String t = "For " + s;
E. s = s + 10;
CDE
3. Given the following declaration
String s = "hello";
Which are legal code?
A. s >> = 2;
B. char c = s[3];
C. s += "there";
D. int i = s.length();
E. s = s + 3;
CDE
解释一下!!!
String s = "Example";
Which are legal code?
A. s >>> = 3;
B. s[3] = "x";
C. int i = s.length();
D. String t = "For " + s;
E. s = s + 10;
CDE
3. Given the following declaration
String s = "hello";
Which are legal code?
A. s >> = 2;
B. char c = s[3];
C. s += "there";
D. int i = s.length();
E. s = s + 3;
CDE
解释一下!!!
两题CDE都是正确的
因为String(字符串)是一个类, 而且s并不是个String组, 所以题中>>= >>>=运算符和s[3]的Array表达是不合法的
String类中包含了length()方法用来返回这个String包含的字母数, 所以题2中C和题3中D都是合法的
String类也支持+运符 用来合并String(字符串) 这个功能叫"concatenation" 而+=运算符实际上就是 s = s + ... concatenation也支持String字符串与其他原始变量int(整数), double(带小数的数字)等的合并 所以题2中D,E和题3中C,E都是合法的