Merge pull request giantray#21 from tangculijier/master

giantray · giantray · commit 173b9fc883f8 · 2016-02-23T18:23:25.000+08:00
Create What's-the-simplest-way-to-print-a-Java-array.md
diff --git a/contents/Check-if-at-least-two-out-of-three-booleans-are-true.md b/contents/Check-if-at-least-two-out-of-three-booleans-are-true.md
@@ -0,0 +1,39 @@
+给3个布尔变量，当其中有2个或者2个以上为true菜返回true
+===
+问题
+给3个boolean变量，a,b,c，当其中有2个或2个以上为true时才返回true？
+最笨的方法：
+```java
+boolean atLeastTwo(boolean a, boolean b, boolean c) 
+{
+    if ((a && b) || (b && c) || (a && c)) 
+    {
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+```
+* 优雅解法1
+```java
+    return a ? (b || c) : (b && c);
+```
+
+* 优雅解法2
+```java
+    return (a==b) ? a : c;
+```
+
+* 优雅解法3
+```java
+   return a ^ b ? c : a
+```
+
+* 优雅解法4
+```java
+    return a ? (b || c) : (b && c);
+```
+
+stackoverflow链接： http://stackoverflow.com/questions/3076078/check-if-at-least-two-out-of-three-booleans-are-true
diff --git a/contents/What's-the-simplest-way-to-print-a-Java-array.md b/contents/What's-the-simplest-way-to-print-a-Java-array.md
@@ -0,0 +1,62 @@
+java中打印一个数组最简单的方法是什么
+===
+问题
+---
+在java中,数组没有重写toString()方法，所以我如果直接调用数组toStrign()方法的话，我会知道得到它的内存地址。像这样:
+```java
+int[] intArray = new int[] {1, 2, 3, 4, 5};
+System.out.println(intArray);     // 有时候会输出 '[I@3343c8b3'
+```
+但是实际上我想要的输出效果是
+```java
+[1, 2, 3, 4, 5]
+```
+所以打印一个数组最简单的方法是什么？我想要的效果是
+```java
+// 数字数组:
+int[] intArray = new int[] {1, 2, 3, 4, 5};
+//输出: [1, 2, 3, 4, 5]
+
+// 对象数组:
+String[] strArray = new String[] {"John", "Mary", "Bob"};
+//输出: [John, Mary, Bob]
+```
+
+回答
+---
+在JAVA5中使用 Arrays.toString(arr) 或 Arrays.deepToString(arr)来打印数组。
+
+不要忘了引入import java.util.Arrays; 
+```java
+package packageName;
+import java.util.Arrays;
+```
+
+```java
+int[] intArray = new int[] {1, 2, 3, 4, 5};
+System.out.println(Arrays.toString(intArray));
+//输出: [1, 2, 3, 4, 5]
+
+String[] strArray = new String[] {"John", "Mary", "Bob"};
+System.out.println(Arrays.deepToString(strArray));
+*//输出: [John, Mary, Bob]
+```
+Arrays.deepToString与Arrays.toString不同之处在于，Arrays.deepToString更适合打印多维数组<br>
+比如： <br>
+
+```java
+String[][] b = new String[3][4];
+		for (int i = 0; i < 3; i++)
+		{
+			for (int j = 0; j < 4; j++)
+			{
+				b[i][j] = "A" + j;
+			}
+		} 
+		System.out.println(Arrays.toString(b));
+		//输出[[Ljava.lang.String;@55e6cb2a, [Ljava.lang.String;@23245e75, [Ljava.lang.String;@28b56559]
+		System.out.println(Arrays.deepToString(b));
+		//输出[[A0, A1, A2, A3], [A0, A1, A2, A3], [A0, A1, A2, A3]]
+		
+```
+stackoverflow链接： http://stackoverflow.com/questions/409784/whats-the-simplest-way-to-print-a-java-array
