例子1(double型强制转换成int型):
直接舍掉小数,只留下整数。
正数: double d = 5.5; int i = (int)d; System.out.println("i=:"i); //输出5double b = 5.9; int i1 = (int)b; System.out.println("i1=:"i1); //输出5double c = 5.2; int i2 = (int)c; System.out.println("i2=:"i2); //输出5~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~负数:double d = -5.5; int i = (int)d; System.out.println("i=:"i); //输出-5double b = -5.9; int i1 = (int)b; System.out.println("i1=:"i1); //输出-5double c = -5.2; int i2 = (int)c; System.out.println("i2=:"i2); //输出-5
例子2(三种取整的方法):
向上取整:Math.ceil(double a)
向下取整:Math.floor(double a)
四舍五入取整:Math.round(double a)
这里要注意Math.round(double a)和Math.rint(double a),四舍五入取整要用Math.round(double a),千万不要用Math.rint(double a),后面我会再详细写Math.round(double a)和Math.rint(double a)的区别
double a = 35;double b = 20;double c = a/b; //等于1.75System.out.println(c); //输出1.75System.out.println(Math.ceil(c)); //向上取整输出2.0System.out.println(Math.floor(c)); //向下取整输出1.0System.out.println(Math.round(c)); //四舍五入取整输出2.0
---------------------
原文:/xmc281141947/article/details/53887126