java除数为零总结

java中浮点数运算中0作除数并不会出现异常，而是：

正数除以0得正无穷，负数除以0得负无穷，0除以0得NaN

同样情况若是整形数运算则会抛出异常

测试用例：

package mytest;

public class DivideTest {

	private void testInt(int dividend, int divisor) {
		try {
			System.out.println("testInt: " + dividend + "/" + divisor + " = "
					+ dividend / divisor);
		} catch (RuntimeException e) {
			System.out.println("testInt exception:" + e.getMessage());
		}
	}

	private void testLong(long dividend, long divisor) {
		try {
			System.out.println("testLong: " + dividend + "/" + divisor + " = "
					+ dividend / divisor);
		} catch (RuntimeException e) {
			System.out.println("testLong exception:" + e.getMessage());
		}
	}

	private void testDouble(double dividend, double divisor) {
		try {
			System.out.println("testDouble: " + dividend + "/" + divisor
					+ " = " + dividend / divisor);
		} catch (RuntimeException e) {
			System.out.println("testDouble exception:" + e.getMessage());
		}
	}

	private void testFloat(float dividend, float divisor) {
		try {
			System.out.println("testFloat: " + dividend + "/" + divisor + " = "
					+ dividend / divisor);
		} catch (RuntimeException e) {
			System.out.println("testFloat exception:" + e.getMessage());
		}
	}

	public static void main(String[] args) {
		DivideTest dt = new DivideTest();

		// 整数
		dt.testInt(0, 0);
		dt.testInt(1, 0);
		dt.testInt(-1, 0);
		System.out.println();

		// 长整形
		dt.testLong(0, 0);
		dt.testLong(1, 0);
		dt.testLong(-1, 0);
		System.out.println();

		// 浮点
		dt.testFloat(0, 0);
		dt.testFloat(1, 0);
		dt.testFloat(-1, 0);
		System.out.println();

		// 双精度
		dt.testDouble(0, 0);
		dt.testDouble(1, 0);
		dt.testDouble(-1, 0);

	}

}