Java Guava IntMath sqrt(int x, RoundingMode mode)用法及代码示例

Guava IntMath类的方法sqrt(int x，RoundingMode mode)返回x的平方根，并使用指定的舍入模式进行舍入。

用法:

public static int sqrt(int x, RoundingMode mode)

异常：

IllegalArgumentException：如果x <0。
ArithmeticException：如果mode为RoundingMode.UNNECESSARY且sqrt(x)不是整数。

Enum RoundingMode

枚举常量	描述
CEILING	舍入模式向正无穷大舍入。
DOWN	舍入模式向零舍入。
FLOOR	舍入模式向负无穷大舍入。
HALF_DOWN	除非两个邻居等距，否则舍入模式将朝“nearest neighbor”舍入。
HALF_EVEN	舍入模式向“nearest neighbor”舍入，除非两个邻居都等距，在这种情况下，向偶数邻居舍入。
HALF_UP	除非两个邻居等距，否则舍入模式将朝“nearest neighbor”舍入。
UNNECESSARY	舍入模式可以断言所请求的操作具有准确的结果，因此不需要舍入。
UP	舍入模式从零舍入。

下面给出了一些示例，以更好地理解实现：

范例1：

// Java code to show implementation of 
// sqrt(int x, RoundingMode mode) method 
// of Guava's IntMath class 
  
import java.math.RoundingMode; 
import com.google.common.math.IntMath; 
  
class GFG { 
  
    // Driver code 
    public static void main(String args[]) 
    { 
        int x1 = 226; 
  
        // Using sqrt(int x, RoundingMode mode) 
        // method of Guava's IntMath class 
        // The RoundingMode HALF_EVEN rounds towards 
        // the nearest neighbor unless both neighbors 
        // are equidistant, in which case, round towards 
        // the even neighbor. 
        int ans1 = IntMath.sqrt(x1, 
                                RoundingMode.HALF_EVEN); 
  
        System.out.println("Square root of x1 is:"
                           + ans1); 
  
        int x2 = 154; 
  
        // Using sqrt(int x, RoundingMode mode) 
        // method of Guava's IntMath class 
        // The RoundingMode FLOOR rounds towards 
        // negative infinity. 
        int ans2 = IntMath.sqrt(x2, 
                                RoundingMode.FLOOR); 
  
        System.out.println("Square root of x2 is:"
                           + ans2); 
    } 
}

输出：

Square root of x1 is:15
Square root of x2 is:12

范例2：

// Java code to show implementation of 
// sqrt(int x, RoundingMode mode) method 
// of Guava's IntMath class 
  
import java.math.RoundingMode; 
import com.google.common.math.IntMath; 
  
class GFG { 
  
    // Driver code 
    public static void main(String args[]) 
    { 
        int x1 = -65; 
        try { 
            // Using sqrt(int x, RoundingMode mode) 
            // method of Guava's IntMath class 
            // The RoundingMode HALF_EVEN rounds towards 
            // the nearest neighbor unless both neighbors 
            // are equidistant, in which case, round towards 
            // the even neighbor. 
  
            // This should throw "IllegalArgumentException" 
            // as x1 < 0 
            int ans1 = IntMath.sqrt(x1, 
                                    RoundingMode.HALF_EVEN); 
        } 
        catch (Exception e) { 
            System.out.println(e); 
        } 
    } 
}

输出：

java.lang.IllegalArgumentException:x (-65) must be >= 0

参考：
https://google.github.io/guava/releases/20.0/api/docs/com/google/common/math/IntMath.html#sqrt-int-java.math.RoundingMode-

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注：本文由纯净天空筛选整理自bansal_rtk_大神的英文原创作品 Java Guava | sqrt(int x, RoundingMode mode) method of IntMath Class。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。