java math类方法_Java Math类scalb（）方法及示例

待我称王封你为后i 2023-03-05 15:53 59阅读 0赞

java math类方法

## 数学类scalb()方法 **(**Math class scalb() method**)** ##

*  **scalb() method** is available in java.lang package.
    
    **scalb()方法**在java.lang包中可用。
 *  **scalb() method** is used to return the a\* 2 raised to the power of scale rounded as an argument as passed in the method. Here, a is the first parameter and scale is the second parameter.
    
    **scalb()方法**用于将a \* 2返还给在方法中传递的作为参数四舍五入的scale幂。 在此， a是第一个参数， scale是第二个参数。
 *  **scalb() method** is a static method, it is accessible with the class name too.
    
    **scalb()方法**是静态方法，也可以使用类名进行访问。
 *  **scalb() method** does not throw any exception.
    
    **scalb()方法**不会引发任何异常。

**Syntax:**

**句法：**

public static float scalb(float a , int sf)
        public static double scalb(double a , int sf);

**Parameter(s):**

**参数：**

*  a – represents number to be scaled by the power of 2.
    
    a –表示要乘以2的幂的数字。
 *  sf (Scale Factor) – represents number power of 2 used to scale a.
    
    sf (缩放因子)–表示用于缩放a的2的幂。

**Return value:**

**返回值：**

The return type of this method is float/double, – it returns the a\*2 raised to the power of sf.

此方法的返回类型为float / double ，它将返回的a \* 2提升为sf的幂。

**Note:**

**注意：**

*  If we pass "NaN", it returns the same value (i.e. "NaN").
    
    如果我们传递“ NaN”，它将返回相同的值(即“ NaN”)。
 *  If we pass "Double.MIN\_EXPONENT" / "Float.MIN\_EXPONENT" or "Double.MAX\_EXPONENT" / "Float.MAX\_EXPONENT", it returns the same value.
    
    如果我们传递“ Double.MIN\_EXPONENT” /“ Float.MIN\_EXPONENT”或“ Double.MAX\_EXPONENT” /“ Float.MAX\_EXPONENT”，则返回相同的值。
 *  If we pass "Double.MAX\_EXPONENT" / "Float.MAX\_EXPONENT", it returns the infinity.
    
    如果我们传递“ Double.MAX\_EXPONENT” /“ Float.MAX\_EXPONENT”，它将返回无穷大。
 *  If we pass infinity as the first argument, it returns the same value with the same sign.
    
    如果我们将无穷大作为第一个参数传递，它将返回具有相同符号的相同值。
 *  If we pass zero (0) as the first argument, it returns the same value with the same sign.
    
    如果我们将零(0)作为第一个参数传递，它将返回具有相同符号的相同值。

### Java程序演示scalb()方法的示例 **(**Java program to demonstrate example of scalb() method**)** ###

// Java program to demonstrate the example of 
    // scalb(double do , int sf) method of Math Class
    
    public class ScalbMethod {
        
        public static void main(String[] args) {
        
            // declaring the variables
            double d1 = -0.0;
            double d2 = -7.0 / 0.0;
            double d3 = 20.0;
            int i = 6;
    
            // Here , we will get (-0.0) because we are passing 
            // parameters whose value is (-0.0,6)
            System.out.println("Math.scalb(d1,i): " + Math.scalb(d1, i));
    
            // Here , we will get (-Infinity) and we are passing 
            // parameters whose value is (-Infinity,6)
            System.out.println("Math.scalb(d2,i): " + Math.scalb(d2, i));
    
            // Here , we will get (20.0 * 2 raised to the power of 6.0) 
            // because are passing parameters whose value is (20.0,6)
            System.out.println("Math.scalb(d3,i): " + Math.scalb(d2, i));
        }
    }

**Output**

**输出量**

E:\Programs>javac ScalbMethod.java
    E:\Programs>java ScalbMethod
    Math.scalb(d1,i): -0.0
    Math.scalb(d2,i): -Infinity
    Math.scalb(d3,i): -Infinity

**Example 2:**

**范例2：**

// Java program to demonstrate the example of 
    // scalb(float fi , int sf) method of Math Class
    
    public class ScalbMethod {
        
        public static void main(String[] args) {
        
            // declaring the variables
            float f1 = -0.0f;
            float f2 = -7.0f / 0.0f;
            float f3 = 20.0f;
            int i = 6;
    
            // Here , we will get (-0.0) because we are passing 
            // parameters whose value is (-0.0,6)
            System.out.println("Math.scalb(f1,i): " + Math.scalb(f1, i));
    
            // Here , we will get (-Infinity) and we are passing 
            // parameters whose value is (-Infinity,6)
            System.out.println("Math.scalb(f2,i): " + Math.scalb(f2, i));
    
            // Here , we will get (20.0 * 2 raised to the power of 6.0) 
            // because are passing parameters whose value is (20.0,6)
            System.out.println("Math.scalb(f3,i): " + Math.scalb(f2, i));
        }
    }

**Output**

**输出量**

E:\Programs>javac ScalbMethod.java
    E:\Programs>java ScalbMethod
    Math.scalb(d1,i): -0.0
    Math.scalb(d2,i): -Infinity
    Math.scalb(d3,i): -Infinity

> 翻译自: [https://www.includehelp.com/java/math-class-scalb-method-with-example.aspx][https_www.includehelp.com_java_math-class-scalb-method-with-example.aspx]

java math类方法

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