# BiConsumer用法

public static void main(String[] args) {
    Map<Integer,Integer> mVal = new HashMap<>();
    mVal.put(1, 10);
    mVal.put(2, 20);
    BiConsumer<Integer,Integer> c = (i,j)->{
        System.out.print(i+","+j+";");
    };
    c.accept(1, 2);
    mVal.forEach(c);
}

Console:

1,2;1,10;2,20;

## Which statement can be inserted into line n1 to print 1,2; 1,10; 2,20;?
**A. BiConsumer<Integer,Integer> c = (i, j) ->
{System.out.print (i + "," + j+
"; ");};**
B. BiFunction<Integer, Integer, String> c = (i, j) ?gt; {System.out.print (i + "," + j+ "; ")};
C. BiConsumer<Integer, Integer, String> c = (i, j) ?gt; {System.out.print (i + "," + j+ "; ")};
D. BiConsumer<Integer, Integer, Integer> c = (i, j) ?gt; {System.out.print (i + "," + j+ "; ");};
- [x] **Answer: A**
:::warning
選項A: 正確用法
選項B~選項D:參數只能輸入兩個
:::

:::info
BiConsumer 有兩個泛型參數，跟Consumer一樣，都有一個accept方法。
BiConsumer的accept方法會先執行，然後才是傳進去的參數
:::

###### tags: `ocpjp`