I want to calculate the earnings from share using vue. I'm subtracting the day closing amount to the start one. I'm not able to display the result on the Dom.
JSfiddle: https://jsfiddle.net/4bep87sf/
This is the code:
let app = new Vue({
el: '#app',
data: {
s: '',
e: '',
tot: '0'
},
watch: {
e: function(){
this.tot = (this.e + this.s);
return this.f;
}
});
Use a computed property:
Vue.config.devtools = false;
Vue.config.productionTip = false;
new Vue({
el: '#app',
data: () => ({
s: 0,
e: 0
}),
computed: {
tot() {
return Number(this.s) + Number(this.e);
}
},
})<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<input v-model="s" type="number">
<input v-model="e" type="number">
<pre>{{s}} + {{e}} = {{tot}}</pre>
</div>Also note you need to cast your values as Number() if you want the sum to be correct. If they're interpreted as strings a + b = ab.
Very close to tao answer. Only "fix" two User experience issues (Not directly related to Vue).
First, if you set a default value (0 for example), when the user focuses input and type "3" the output is 03! (or 30) ==> Very annoying (Especially on mobile).
Sometimes it's better to set the input value to null and show input placeholder (Fix this annoying issue).
The output 0 + 0 = 0 does not contribute too much to the user. Sometimes it's better to put the sum inside v-if.
<p v-if="number1 && number2">{{total}}</p>
Vue.config.devtools = false;
Vue.config.productionTip = false;
new Vue({
el: '#app',
data: () => ({
number1: {
type: Number,
value: null,
placeholder: "Enter number 1",
},
number2: {
type: Number,
value: null,
placeholder: "Enter number 2",
}
}),
computed: {
total() {
return Number(this.number1.value) + Number(this.number2.value);
}
},
})span{
color: red;
font-weight: bold
}<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<h3></h3>
<div>
<label>Number 1:</label>
<input autofocus v-model="number1.value" type="number" v-bind:placeholder="number1.placeholder">
</div>
<div>
<label>Number 2:</label>
<input v-model="number2.value" type="number" v-bind:placeholder="number2.placeholder">
</div>
<p>Total:<span v-if="number1.value && number2.value"> {{total}}</span></p>
</div>v-model.lazy also sometimes useful for calucations:
By default, v-model syncs the input with the data after each input event (with the exception of IME composition, as stated above). You can add the lazy modifier to instead sync after change events. https://v2.vuejs.org/v2/guide/forms.html#lazy
echanges, settotequal toe+s". That makes sense, butreturn this.fdoes not, and alsofis not defined. Another issue is you did not show the template, so we can't guess what you intend in the DOM.