I have an array of objects containing some information. I am not able to render them in the order I want and I need some help with that. I render them like this:
this.state.data.map(
(item, i) => <div key={i}> {item.matchID} {item.timeM} {item.description}</div>
)
Is it possible to sort them ascending with item.timeM in that map()-function or do I have to sort them before i use map?
This might be what you're looking for:
// ... rest of code
// copy your state.data to a new array and sort it by itemM in ascending order
// and then map
const myData = [].concat(this.state.data)
.sort((a, b) => a.itemM > b.itemM ? 1 : -1)
.map((item, i) =>
<div key={i}> {item.matchID} {item.timeM}{item.description}</div>
);
// render your data here...
The method sort will mutate the original array . Hence I create a new array using the concat method. The sorting on the field itemM should work on sortable entities like string and numbers.
You will need to sort your object before mapping over them. And it can be done easily with a sort() function with a custom comparator definition like
var obj = [...this.state.data];
obj.sort((a,b) => a.timeM - b.timeM);
obj.map((item, i) => (<div key={i}> {item.matchID}
{item.timeM} {item.description}</div>))
this.state.data.sort((a, b) => a.item.timeM > b.item.timeM).map(
(item, i) => <div key={i}> {item.matchID} {item.timeM} {item.description}</div>
)