It seems that java originally has a class called BigDecimal.
Declaring a variable of type BigDecimal for the first time I thought that I should use the valueOf () method when I finally wanted to convert a variable of BigDecimal type to String type, but it seems that BigDecimal has a method for type conversion.
Next, in the switch statement, the calculation results of right and left are stored in decimalValue.
And the point of interest is type conversion. String decimalValue1 = decimalValue.toString(); The part of is type conversion.
First, prepare decimalVlue1 to put the converted value Next, the decimalValue is converted using the method that BigDecimal has called toString ().