Java StrictMath toIntExact()方法及示例

java.lang.StrictMath.toIntExact() 是Java中一个内置的方法，用于返回长参数的值。如果结果溢出了一个int，它将抛出一个异常。由于toIntExact(long num)是静态的，所以创建对象不是强制性的。

语法。

public static int toIntExact(long num)

参数。该方法接受一个长类型的参数num，其值将被返回。

返回值。该方法将参数返回为一个int。

异常情况。如果参数溢出为一个int，则抛出 ArithmeticException

例子
输入: num = 2727l
输出:2727

输入: num = -86262l
输出:-86262

以下程序说明了java.lang.StrictMath.toIntExact()方法。

程序1 :

// Java program to demonstrate working
// of java.lang.StrictMath.toIntExact() method
  
import java.lang.StrictMath;
  
class Geeks {
  
    // driver code
    public static void main(String args[])
    {
  
        // Get the long value
        // whose IntExact value is needed
        long num = 266526l;
  
        // Get the IntExact value
        // using toIntExact() method
        int intvalue = StrictMath.toIntExact(num);
  
        // Print the IntExact value
        System.out.print("IntExact value of "
                         + num + " = " + intvalue);
    }
}

输出:

IntExact value of 266526 = 266526

程序2

// Java program to demonstrate working
// of java.lang.StrictMath.toIntExact() method
  
import java.lang.StrictMath;
  
class Geeks {
  
    // driver code
    public static void main(String args[])
    {
  
        // Get the long value
        // whose IntExact value is needed
        long num = -7226526l;
  
        // Get the IntExact value
        // using toIntExact() method
        int intvalue = StrictMath.toIntExact(num);
  
        // Print the IntExact value
        System.out.print("IntExact value of "
                         + num + " = " + intvalue);
    }
}

输出:

IntExact value of -7226526 = -7226526

程序3： 演示ArithmeticException

// Java program to demonstrate working
// of java.lang.StrictMath.toIntExact() method
  
import java.lang.StrictMath;
  
class Geeks {
  
    // driver code
    public static void main(String args[])
    {
  
        try {
            // Get the long value
            // whose IntExact value is needed
            long num = 654456645546l;
  
            System.out.println("Trying to get "
                               + "IntExact value of: "
                               + num);
  
            // Get the IntExact value
            // using toIntExact() method
            int intvalue = StrictMath.toIntExact(num);
  
            // Print the IntExact value
            System.out.print("IntExact value of "
                             + num + " = " + intvalue);
        }
        catch (Exception e) {
            System.out.println("Exception thrown: " + e);
        }
    }
}

输出:

Trying to get IntExact value of: 654456645546
Exception thrown: java.lang.ArithmeticException: integer overflow