java课程设计报告-计算器

java课程设计报告—计算器javapublicclassCalculatorLogic{privateStringcurrentInput;privatedoublepreviousNumber;privatecharcurrentOperator;privatebooleanisNewInput;privatebooleanhasDecimalPoint;publicCalculatorLogic(){reset();}privatevoidreset(){currentInput="";previousNumber=0;currentOperator='\0';isNewInput=true;hasDecimalPoint=false;}publicStringprocessDigit(chardigit){if(isNewInput){currentInput="";isNewInput=false;}currentInput+=digit;returncurrentInput;}publicStringprocessDecimalPoint(){if(isNewInput){currentInput="0";isNewInput=false;}if(!hasDecimalPoint){currentInput+=".";hasDecimalPoint=true;}returncurrentInput;}publicStringprocessOperator(charoperator){if(!currentInput.isEmpty()){previousNumber=Double.parseDouble(currentInput);currentOperator=operator;isNewInput=true;hasDecimalPoint=false;}returncurrentInput;//此时显示的仍是之前输入的数字，直到输入新数字}publicStringcalculateResult(){if(currentInput.isEmpty()||currentOperator=='\0'){returncurrentInput;}doublecurrentNumber;try{currentNumber=Double.parseDouble(currentInput);}catch(NumberFormatExceptione){return"错误";}doubleresult=0;switch(currentOperator){case'+':result=previousNumber+currentNumber;break;case'-':result=previousNumber-currentNumber;break;case'×':result=previousNumber*currentNumber;break;case'÷':if(currentNumber==0){reset();return"除数不能为零";}result=previousNumber/currentNumber;break;default:return"错误";}//处理结果显示，避免如1.0这样的显示，转为1currentInput=(result==(long)result)?String.valueOf((long)result):String.valueOf(result);hasDecimalPoint=currentInput.contains(".");currentOperator='\0';isNewInput=true;returnc