How to show only one button per every distinct date ?
can i use two v-for loops ? how to select distinct values in my loop?
<div v-for="question in allQuestions" >
<button v-for="date in question.date">
{{date}}
</button>
</div>
allQuestions : []
question : {'id' : '123' , 'date' : '25'}
You can use Set:
The
Setobject lets you store unique values of any type, whether primitive values or object references.
MDN's example:
const numbers = [2, 3, 4, 4, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 5, 32, 3, 4, 5]
console.log([...new Set(numbers)])Just modify it to your needs.
allQuestions array are not unique
Set works just fine.Use reduce to execute a reducer function on each item of the array, then merge the individual matches into the existing object with assign. This merging process takes care of removing (or actually replacing) duplicate items.
const vm = new Vue({
el: '#app',
data() {
return {
allQuestions: [
{ id: '123', date: '14' },
{ id: '456', date: '2' },
{ id: '933', date: '2' },
{ id: '789', date: '7' },
{ id: '220', date: '14' }
]}
},
computed: {
uniqueQuestions() {
return this.allQuestions.reduce((seed, current) => {
return Object.assign(seed, {
[current.date]: current
});
}, {});
}
}
});<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<div v-for="question in uniqueQuestions" :key="question.date">
<button v-for="date in question.date">
{{date}}
</button>
</div>
</div>
question.date to be like. In your example, you had it as string but I don't get why you would v-for the individual dates as char?You can use computed to display an array of all your questions sorted by date.
allQuestions : [ question : {'id' : '123' , [{'date' : '25'},{'date' : '25'},{'date' : '27'}]}, ]<button v-for="date in question.date"> {{date.id}} </button>allQuestionsarray have nothing in it. put yourquestionobject inside yourallQuestionarray.