All of the code is self-explanatory and pretty much complete.
What the code does:
- Calculates using onscreen numerics and operators
- Validates any erroneous operations, such as 4 ** 8 or *9
Good features of the code:
- The code has separate functions handling the validation, evaluation, etc.
- It's much more modular
Recommended further improvements on the following basis:
- Understandability
- Modularity
- Efficiency
- Repetition
(function() { // private variable accessible by all the functions below var keys, input = "", result; function equate() { console.log('the equal button was pressed') result = eval(input); $('.screen').text(result); } function clear() { input = ""; $('.screen').text(input); result = ""; console.log('the clear button was pressed') } function isOperator(_input) { return (['+', '-', '*', '%', '/', '.'].indexOf(_input) >= 0) } function lastInputIsOperator() { return isOperator(input.charAt(input.length - 1)) }; // created a new module validate input and moved it out of expressInMath function validateInput(_input) { // prevents any operations like ++, -- etc if (isOperator(_input)) { // check the last character input if (lastInputIsOperator(input)) { if (input.length < 1) { input = ''; } else if (_input === '.' && input.indexOf('.') >= 0) { console.log('invalid'); } else { input = input.slice(0, input.length - 1) + _input; } // avoids any operation of the kind 0.6.7.5 } else if (_input === '.' && input.indexOf('.') >= 0) { console.log('invalid'); } else { if (input.length < 1) { input = ''; } else { input += _input; } } console.log('Operation prohibited') } else { input += _input; } } function expressInMath(_input) { validateInput(_input); result = ''; $('.screen').text(input); } // analyzes the keys pressed by the user function analyze() { //private vars let $this = $(this), _input = $this.text(); // if clear button is pressed if (_input == "C") { clear(); } // if equals to button is pressed else if (_input == "=") { equate(); } // if key or operator button is pressed else { expressInMath(_input); } } // self invoking initializing function (function initialize() { $('#calculator span').on('click', analyze); }()); }())/* Basic reset */ * { margin: 0; padding: 0; box-sizing: border-box; font: bold 14px Arial, sans-serif; } html { height: 100%; background: radial-gradient()circle, #fff, #ccc; background-size: cover; } #calculator { width: 375px; height: 340px; margin: 100px auto; padding: 20px 20px 9px; background: yellowgreen; border-radius: 3px; box-shadow: 0px 4px #009de4, 10px 15px 0px rgba(0, 0, 0, 0.2); } /* top portion */ .top span.clear { float: left; } .top .screen { height: 40px; width: 212px; float: right; background: rgba(0, 0, 0, 0.2); box-shadow: inset 0px 4px #009de4; padding: 0px 10px; /* typography */ font-size: 17px; line-height: 40px; color: white; text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2); text-align: right } /* Clear floats */ /*.keys, .top {overflow: hidden};*/ .keys span, .top span.clear { float: left; position: relative; top: 0; cursor: pointer; width: 66px; height: 40px; background: white; border-radius: 2px; box-shadow: 0px 4px rgba(0, 0, 0, 0.2); margin: 0 7px 11px 0; line-height: 40px; text-align: center; user-select: none; } .keys span.operator { background: #FFF0F5; margin-right: 0px; } .keys span.eval { background: #f1ff92; box-shadow: 0px 4px #9da853; color: #888e5f; } .top span.clear { background: #ff9fa8; box-shadow: 0px 4px #ff7c87; color: white; } /* hover effect */ .keys span:hover { background: #9c89f6; box-shadow: 0px 4px #6b54d3; color: white; } .keys span.eval:hover { background: #f1ff92; box-shadow: 0px 4px #9da853; color: #888e5f; } .top span.clear:hover { background: #ff9fa8; box-shadow: 0px 4px #ff7c87; color: white; } /* active state */ .keys span:active { box-shadow: 0px 4px #6b54d3; top: 4px; } .keys span.eval:active { box-shadow: 0px 4px #9da853; top: 4px; } .top span.clear:active { top: 4px; box-shadow: 0px 0px #d3545d; }<html> <head> <link rel="stylesheet" href="/style.css"> </head> <body> <div id="calculator"> <div class="top"> <span class="clear">C</span> <div class="screen">0</div> </div> <div class="keys"> <span>7</span> <span>8</span> <span>9</span> <span>+</span> <span>4</span> <span>5</span> <span>6</span> <span>-</span> <span>1</span> <span>2</span> <span>3</span> <span>/</span> <span class="num">0</span> <span class="decimal">.</span> <span class="eval">=</span> <span>*</span> </div> </div> <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script> <script src="new.js"></script> <!-- <script src="script.js"></script> --> </body> </html>
