math类中的几种取整方式

方法名 作用
ceil 天花板,即向上取整,结果大于等于原值
floor 地板,即向下取整,结果小于等于原值
round 四舍五入,算法为Math.floor(x+0.5)

代码示例

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public class {
public static void main(String[] args) {
System.out.println(Math.floor(-10.4));
System.out.println(Math.floor(-10.6));
System.out.println(Math.floor(10.4)); //10.0
System.out.println(Math.floor(10.6)); //10.0
System.out.println(Math.ceil(-10.4)); //-10.0
System.out.println(Math.ceil(-10.6)); //-10.0
System.out.println(Math.ceil(10.4)); //11.0
System.out.println(Math.ceil(10.6)); //11.0
System.out.println(Math.round(-10.1)); //-10
System.out.println(Math.round(-10.5)); //-10
System.out.println(Math.round(-10.9)); //-11
System.out.println(Math.round(10.1)); //10
System.out.println(Math.round(10.5)); //11
System.out.println(Math.round(10.9)); //11
}
}