引言
随着工作时间的推移，参加过的面试也是挺多的。记录下参与面试中的一些经典代码阅读题。
对象与Map
Map取值测试:
package net.xqlee.project.demo;
public class Person {
public Person(String name) {
this.name = name;
}
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
package net.xqlee.project.demo;
import java.util.HashMap;
import java.util.Map;
public class DemoMap {
public static void main(String[] args) {
Map map = new HashMap<>();
map.put(new Person("leftso"), "leftso");
map.put(new Person("小左"), "小左");
String personName = map.get(new Person("leftso"));
System.out.println(personName);
}
}
控制台打印结果(提示:鼠标选中空白区域查看答案):
null
while循环
package net.xqlee.project.demo;
public class DemoWhile {
public static void main(String[] args) {
int y = 7;
int x = 4;
while ((x += 2) < y) {
do {
System.out.print(x + " ");
} while (++y < 9);
}
}
}
控制台输出结果(提示:鼠标选中空白区域查看答案):
6 6 8
整数Integer
package net.xqlee.project.demo;
public class DemoInteger {
public static void main(String[] args) {
Integer a = 20, b = 20, c = 150, d = 150;
int a1 = 20, b1 = 20, c1 = 150, d1 = 150;
System.out.print((a == b) + " " + (c == d) + " " + (a1 == b1) + " " + (c1 == d1));
}
}
控制台输出:
true false true true
集合List
package net.xqlee.project.demo;
import java.util.ArrayList;
import java.util.List;
public class DemoList {
public static void main(String[] args) {
List list=new ArrayList<>();
list.add(new Integer(20));
list.add(new Integer(30));
list.add(new Float(2.2));
for (Integer integer : list) {
System.out.print(integer+" ");
}
}
}
控制台输出:
编译时错误
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