I've got a data set that's several hundred elements long. I need to loop through the arrays and objects and determine if the data in them is less than a certain number (in my case, 0). If it is, I need to remove all those data points which are less than zero from the data set.

I've tried .pop and .slice but I'm not implementing them correctly. I was trying to push the bad data into its own array, leaving me with only the good data left.

Here's my JS

for (var i = 0; i < data.length; i++) {
    if (data[i].high < 0) {
       console.log(data[i].high)
       var badData = [];
       badData.push(data.pop(data[i].high));
       console.log(data[i].high)
   }  
}

I've got a data set that's several hundred elements long. I need to loop through the arrays and objects and determine if the data in them is less than a certain number (in my case, 0). If it is, I need to remove all those data points which are less than zero from the data set.

I've tried .pop and .slice but I'm not implementing them correctly. I was trying to push the bad data into its own array, leaving me with only the good data left.

Here's my JS

for (var i = 0; i < data.length; i++) {
    if (data[i].high < 0) {
       console.log(data[i].high)
       var badData = [];
       badData.push(data.pop(data[i].high));
       console.log(data[i].high)
   }  
}

• javascript
• arrays

• This would be a good case for .filter() – Ryan Wilson Commented Mar 9, 2018 at 18:12
• .pop() does not accept any arguments. It simply pops off the last element in the array. It seems like you are looking for .splice() instead, so you can remove an element at a specific index, yes? – mhodges Commented Mar 9, 2018 at 18:13
• Possible duplicate of javascript filter array of objects – mhodges Commented Mar 9, 2018 at 18:19

2 Answers 2

I'd go with .filter():

const result = data.filter(row => row.high > 0);

In case you need the bad results too.

const { good, bad } = data.reduce((acc, row) => {
    const identifier = row.high > 0 ? 'good' : 'bad';
    acc[identifier].push(row);
    return acc;
}, { bad: [], good: [] });