Java BigDecimal toEngineeringString()方法及实例

java.math.BigDecimal .toEngineeringString()方法用来表示当前的BigDecimal，该方法被调用时，如果需要使用指数符号，则用工程符号表示为字符串形式。BigDecimal的字符串表示与toString()方法中描述的相同，只是如果使用指数符号，10的幂被调整为3的倍数（工程符号），这样非零值的整数部分将在1到999之间。

语法

public String toEngineeringString()

参数： 该方法不接受任何参数。

返回值： 该方法返回该BigDecimal数字的工程字符串表示。

下面的程序说明了java中toEngineeringString()方法的使用

例子1：将BigDecimal转换为Engineering String的例子，没有指数符号。

// Java program to demonstrate
// toEngineeringString() method of BigDecimal
  
import java.math.*;
  
class GFG {
    public static void main(String[] args)
    {
        // Creating a BigDecimal object
        BigDecimal b;
  
        // Object of String to hold the number
        String input = "012345678901234567"
                       + "8901234567890123"
                       + "4567890123456789"
                       + "0123456789012345"
                       + "6789012345678901"
                       + "2345678901234567"
                       + "8901234567890123"
                       + "4567890123456789"
                       + "0123456789012345"
                       + "6789012345678901"
                       + "2345678901234567"
                       + "8901234567890123"
                       + "4567890123456789"
                       + "0123456789012345"
                       + "6789012345678901"
                       + "2345678901234567"
                       + "8901234567890123"
                       + "4554324324362432"
                       + "7674637264783264"
                       + "7832678463726478"
                       + "4635463263453264"
                       + "654632498739473";
  
        // Converting to BigDecimal
        b = new BigDecimal(input);
  
        // Apply toEngineeringString() method
        String s = b.toEngineeringString();
  
        // Print the result
        System.out.println(s);
    }
}

输出。

1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234554324324362432767463726478326478326784637264784635463263453264654632498739473

例2：将BigDecimal转换为带有指数符号的工程字符串的例子

// Java program to demonstrate
// toEngineeringString() method of BigDecimal
  
import java.math.*;
  
class GFG {
    public static void main(String[] args)
    {
  
        // Create a BigDecimal object
        BigDecimal a = new BigDecimal("4536785E10");
  
        // Create a String object
        String s;
  
        // apply toEngineeringString() method
        s = a.toEngineeringString();
  
        // print the result
        System.out.println(s);
    }
}

输出。