基于JavaScript的公式解释器 - 7 【算术操作符的实现】

算术操作符包括 +、-、*、/、%

 

算术操作符

文件：OperatorMathematic.js

function OperatorMathematic() { this.DeriveFrom(new OperatorBinaryBase()); this.set_ClassName("OperatorMathematic"); this.set_Sign("undefined");};function OperatorAdd() { this.DeriveFrom(new OperatorMathematic()); this.set_ClassName("OperatorAdd"); this.set_Sign("+");};OperatorAdd.prototype.Evaluate = function(operands) { var values = this._getTwoNumberOperands(operands); return new OperandNumber(values[0].get_Value() + values[1].get_Value());};function OperatorSubtract() { this.DeriveFrom(new OperatorMathematic()); this.set_ClassName("OperatorSubtract"); this.set_Sign("-");};OperatorSubtract.prototype.Evaluate = function(operands) { var values = this._getTwoNumberOperands(operands); return new OperandNumber(values[0].get_Value() - values[1].get_Value());};function OperatorMultiply() { this.DeriveFrom(new OperatorMathematic()); this.set_ClassName("OperatorMultiply"); this.set_Sign("*");};OperatorMultiply.prototype.Evaluate = function(operands) { var values = this._getTwoNumberOperands(operands); return new OperandNumber(values[0].get_Value() * values[1].get_Value());};function OperatorDivide() { this.DeriveFrom(new OperatorMathematic()); this.set_ClassName("OperatorDivide"); this.set_Sign("/");};OperatorDivide.prototype.Evaluate = function(operands) { var values = this._getTwoNumberOperands(operands); return new OperandNumber(values[0].get_Value() / values[1].get_Value());};function OperatorModule() { this.DeriveFrom(new OperatorMathematic()); this.set_ClassName("OperatorModule"); this.set_Sign("%");};OperatorModule.prototype.Evaluate = function(operands) { var values = this._getTwoNumberOperands(operands); if (values[1].get_Value() == 0) throw new Exception(this, "Evaluate", "Divide by zero"); return new OperandNumber(values[0].get_Value() % values[1].get_Value());};