I don't understand this 1 line in the svelte code
Ignore the comments. Why
numbers=numbers is used in the function
<script>
let numbers = [1, 2, 3, 4];
function addNumber() {
// numbers = [...numbers, numbers.length+1];
//numbers[numbers.length] = numbers.length+1
numbers.push(numbers.length + 1);
numbers = numbers;
}
$: sum = numbers.reduce((t, n) => t + n, 0);
</script>
<p>{numbers.join(' + ')} = {sum}</p>
<button on:click={addNumber}>
Add a number
</button>2 Replies
from what i understand, assigning the same value to a variable causes a refresh in the UI. Without it the button won't do anything. Am i correct?
you are correct. The way the reactivity works,
numbers.push doesn't trigger an update. By assigning numbers to itself, you trigger that reactivity update which also updates the UI