可变参数列表 java

Thinking in Java(3)

1. 可变参数列表

1.1 使用Object数组参数

import java.util.*;

class A {}

public class VarArgs {
static void printArray(Object[] args) {
for(Object obj : args) {
System.out.println(obj + " ");
}
System.out.println();
}
public static void main(String[] args) {
printArray(new Object[] {new Integer(47), new Float(3.14), new Double(11.11)});
printArray(new Object[] {"one", "two", "three"});
printArray(new Object[] { new A(), new A(), new A() });
}
}

result
47
3.14
11.11

one
two
three

A@69d4c4b7
A@fbf00a9
A@44c45f52

1.2 使用可变参数列表

import java.util.*;

class A {}

public class NewVarArgs {
static void printArray(Object... args) {
for(Object obj : args) {
System.out.println(obj + " ");
}
System.out.println();
}

public static void main(String[] args) {
printArray(new Integer(47), new Float(3.14), new Double(11.11));
printArray(47, 3.14, 11.11);
printArray("one", "two", "three");
printArray(new A(), new A(), new A());
printArray((Object[])new Integer[] {1, 2, 3, 4});
printArray();
}
}

47
3.14
11.11

47
3.14
11.11

one
two
three

A@384e23c3
A@120df416
A@5213d99c

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