I want to create new Array from old array where each elements length is greater than its previous element. I have a old array like below:
Arr=[[2,3],[1,2],[2,4,5],[6,6,3],[3,2,1],[4,2,3],[4,2,1,2],[2,1,4,5]]
Now I have to create a new array like below from above array:
newArr = [[2,3],[2,4,5],[4,2,1,2]]
Using Javascript.
We loop over all array and if current length less then next, we push element in result and change a current length
const findArray = () => {
let currentLength = 0
const result = []
for (let i = 0; i < arr.length; i += 1) {
if (arr[i].length > currentLength) {
result.push(arr[i])
currentLength = arr[i].length
}
}
return result
}
I wood here to demonstrate this code with real value (the output is printed in screen)
<!DOCTYPE html>
<html>
<body>
<p>Click the button to create an array, then display its length.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var Arr=[[2,3],[1,2],[2,4,5],[6,6,3],[3,2,1],[4,2,3],[4,2,1,2],[2,1,4,5]];
var text = "";
var len=0;
var i;
for (i = 0; i < Arr.length; i++) {
if (len < Arr[i].length )
{text += Arr[i] + "<br>"; len=Arr[i].length;}
}
document.getElementById("demo").innerHTML = text;
}
</script>
</body>
</html>
Result is:
2,3
2,4,5
4,2,1,2
You could take a closure over the next wanted length and filter the array by checking the index or actual length. If one of the both conditions is true, set l to the next expected length.
const
array = [[2, 3], [1, 2], [2, 4, 5], [6, 6, 3], [3, 2, 1], [4, 2, 3], [4, 2, 1, 2], [2, 1, 4, 5]],
result = array.filter(
(l => ({ length }) => (!l || l === length) && (l = length + 1))
(0)
);
console.log(result);