Calculator

Build a Calculator with CSS Grid and vue.js.

View demo

html

<div id="calculator">
  <div id="result">
    <span>{{ valueDisplayed }}</span>
  </div>
  <div id="pad">
    <div class="btn" id="clear" @click="clear">C</div>
    <div class="btn" @click="handleOp('/')">/</div>
    <div class="btn" @click="handleDigit(7)">7</div>
    <div class="btn" @click="handleDigit(8)">8</div>
    <div class="btn" @click="handleDigit(9)">9</div>
    <div class="btn" @click="handleOp('x')">x</div>
    <div class="btn" @click="handleDigit(4)">4</div>
    <div class="btn" @click="handleDigit(5)">5</div>
    <div class="btn" @click="handleDigit(6)">6</div>
    <div class="btn" @click="handleOp('-')">-</div>
    <div class="btn" @click="handleDigit(1)">1</div>
    <div class="btn" @click="handleDigit(2)">2</div>
    <div class="btn" @click="handleDigit(3)">3</div>
    <div class="btn" @click="handleOp('+')">+</div>
    <div id="zero" class="btn" @click="handleDigit(0)">0</div>
    <div id="equal" class="btn" @click="handleOp('=')">=</div>
  </div>
</div>

Css

html
  background: #CCC
  font-family: sans-serif
body
  display: grid
  justify-items: center
  align-items: center
  height: 100vh
#calculator
  border: 2px solid #222
  border-radius: 4px
  max-width: 350px
#result
  font-size: 42px
  width: 100%
  height: 70px
  box-sizing: border-box
  display: grid
  padding: 10px
  justify-items: end
  align-items: center
  border-bottom: 2px solid #222
#pad
  display: grid
  grid-template-columns: repeat(4, minmax(60px, 1fr))
  grid-gap: 10px
  padding: 15px
.btn
  cursor: pointer
  font-size: 20px
  display: grid
  padding: 15px 10px
  justify-items: center
  align-items: center
  color: #FAFAFA
  border: 1px solid #222
  border-radius: 4px
  background: #777
#clear
  background: steelblue
  grid-column: 1/4
#zero
  grid-column: 1/4
#equal
  background: seagreen

JavaScript

var app = new Vue({
  el: '#calculator',
  data () {
    return {
      currentValue: 0,
      savedValue: false,
      currentOp: false
    }
  },
  methods: {
    clear () {
      this.currentValue = 0
      this.savedValue = false
      this.currentOp = false
    },
    handleDigit (digit) {
      if (this.currentOp === '=') {
        this.savedValue = false
      }
      this.currentValue = this.currentValue * 10 + digit
    },
    handleOp (op){
      if (this.currentOp) {
         this.process()
      }
      else {
        this.savedValue = this.currentValue
      }
      this.currentValue = 0
      this.currentOp = op      
    },
    process() {
      if (this.currentOp === '+') {
        this.savedValue += this.currentValue
      }
      else if (this.currentOp === '-') {
        this.savedValue -= this.currentValue
      }
      else if (this.currentOp === 'x') {
        this.savedValue *= this.currentValue
      }
      else if (this.currentOp === '/') {
        this.savedValue /= this.currentValue
      }
      else if (this.currentOp === '=' && this.currentValue) {
        this.savedValue = this.currentValue
      }
      this.currentValue = 0
      this.currentOp = false
    }
  },
  computed: {
     valueDisplayed () {
      return this.savedValue ? 
        this.currentValue ? 
        this.currentValue : this.savedValue
        : this.currentValue
    }
  }
})

Author

Lova

Demo

See the Pen Build a Calculator with CSS Grid (and powered by Vue) by Lova (@lovasoa) on CodePen.