# Counting the clusters of positive numbers - JavaScript Arrays

Let’s say, we have an array of numbers like this −

const arr = [-1,-2,-1,0,-1,-2,-1,-2,-1,0,1,0];

We are required to write a JavaScript function that counts the consecutive groups of non-negative (positives and 0) numbers in the array.

Like here we have consecutive non-negatives from index 3 to 3 (only one element, but still a cluster) which forms one group and then from 9 to end of array forms the second group.

Therefore, for this array, the function should return 2.

## Example

Following is the code −

const arr = [-1,-2,-1,0,-1,-2,-1,-2,-1,0,1,0];
const positiveClusters = arr => {
return arr.reduce((acc, val, ind) => {
if(val >= 0 && (arr[ind+1] < 0 || typeof arr[ind+1] === 'undefined')){
acc++;
};
return acc;
}, 0);
};
console.log(positiveClusters(arr));

## Output

This will produce the following output in console −

2

Updated on: 18-Sep-2020

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