easraka.blogg.se - Console calculator

#Console calculator how to
#Console calculator update
#Console calculator software
#Console calculator code
#Console calculator free

If yes, then property lookup is executed for the particular operator in the performCalc object and the function matching the operator is then executed. The else if statement attached to manageOperator Function validates if an operator is present already. '=': (firstInput, secondInput) => secondInput '-': (firstInput, secondInput) => firstInput - secondInput, '+': (firstInput, secondInput) => firstInput + secondInput, '*': (firstInput, secondInput) => firstInput * secondInput, '/': (firstInput, secondInput) => firstInput / secondInput,

Then we’ll create a new object named as performCalc below manageOperator with the listed attributes: Keys.addEventListener('click', (event) => = calcĬonst output = performCalc(firstInput, input) Now we’ll check and find out which key was clicked.Ĭonst keys = document.querySelector('.calc-keys') Usually in calculator’s keys are in the following 4 sets: operators (+, -, *, /, =), numbers(0-9), a reset key (AC), and a decimal (.) key. This function will be called whenever there is a need to change the display content within the app.Ĭonst disp = document.querySelector('.calc-screen')

#Console calculator update

In order to perform the above operation well, we will define a function which will update the value of the screen with the dispValue content. We need to pull the value of dispValue attribute on the calculator screen which should be ‘0’ by default. Initially, the calculator screen will show nothing.

#Console calculator how to

How to build a javascript calculator? are explain below: Updating the Display Screen Here, dispValue will hold the string value to be shown on the screen, firstInput will hold the first input value, waitForSecondInput is a flag that will check whether the expression is fine or another input needs to be entered, and operator attribute will hold value of operator. The CALC object have all the necessary attributes to check whether a valid expression is passed. Hence, we’ll start with building an object ‘CALC’ which will keep info about all the above three things. the first input (42), the second input (15) and the operator pressed (+). In order to build a valid expression, we should be informed about few things i.e.

#Console calculator software

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#Console calculator free

Then your application might get structured into a Calculator and a CalculationTask class with methods like readTask(), compute() and printResult().Start Your Free Software Development Course Your next step should be to learn about object orientation. of the three input elements (two numbers and operation), why do you just repeat the operation in the result output? Some outputs are unnecessary, some info could be added. Run your program and have a critical look at the inputs and outputs.At least separate user interface and algorithmic tasks.

Don't do everything in the main() method.

(eo + "- \n Your Result: "+ ( firstNumber - secondNumber )) ĭefault: ("\n Please select a valid character") (eo + "+ \n Your Result: "+ ( firstNumber + secondNumber )) (eo + "/ \n Your Result: "+ ( firstNumber / secondNumber )) (eo + "* \n Your Result: "+ ( firstNumber * secondNumber )) Scanner scanner = new Scanner(System.in) So, a formally-improved version might be: import To me, that looks like old-fashioned C language from the 1970s.

Don't declare variables some lines before you use them (like you did with xe and xo).

A variable name should clearly tell what its content means.

Use variable names like "operation" (good example), and avoid names like "xe", "xo", or "eo".

Every reader of your program will see that you are closing your resource, even without your comment.

You can omit comments like //Close if the next line does exactly this, explicitly.

Use spacing consistently (insert a space after an opening parenthesis or not?).

#Console calculator code

Use an IDE that can automatically maintain a proper code indentation (the "switch" line is out of alignment).

We Java programmers are REALLY used to these conventions, so programs that don't follow them confuse us and lead to mis-interpretations. variables and fields should begin lower-case, closing braces should be placed on their own line.

Read and follow the Java code conventions: e.g.

Let me suggest some improvements for the next program version. ("\n Select between (*,/,+,-)\n Type out the character in a single letter: ") Ĭase "*": (EO + "* \n Your Result: "+( xe * xo )) break Ĭase "/": (EO + "/ \n Your Result: "+ ( xe / xo )) break Ĭase "+": (EO + "+ \n Your Result: "+ ( xe + xo )) break Ĭase "-": (EO + "- \n Your Result: "+( xe - xo )) break ĭefault: ("\n Please select a valid character") } Just started out on Java and I would like to know your opinions on this calculator I made, took me 30 minutes so you can be rough.