不清楚为什么在尝试将 JSON 功能添加到数组时会得到奇怪的结果

Question

I'm working on a function in leaflet that changes the style weight of the most recent object in a JSON response. That's beside the point though, because I can't properly get the JSON objects into an array.

When I run console.log(dates) in order to see if they were pushed to the dates array I return this in the console. A bunch of empty arrays, amounting to the number of dates in the JSON response.

When I run console.log(time) to ensure I am in fact reaching the correct json feature I receive the dates (epoch format) as expected, but can not understand why they will not be pushed into the array dates . Any ideas?

Function

//most recent earthquake identifer

function mostRecent(time) {
    var dates=[];
    for (var i = 0; i < time.length; i++) {
        dates.push(time[i])
    }
    console.log(dates)
return true
}

Javascript

// adds geojson feed of earthquakes from USGS url (must create a function to layer it on leaflet)

$.getJSON('https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson', function(earthQuakes) {
    var points = L.geoJSON(earthQuakes, {
        filter: eqFilter,
        onEachFeature: function (feature, layer) {  // binds data in geosjon to a popup
            var eqDate = new Date(feature.properties.time); // converts epoch date
            layer.bindPopup(
                '<b>Location: </b>' + feature.properties.place + '<br>' +
                '<b>Magnitude: </b>' + feature.properties.mag + '<br>' +
                '<b>Depth: </b>' + feature.geometry.coordinates[2] + 'km' + '<br>' +
                '<b>Time: </b>' + eqDate.toGMTString() + '<br>' +
                '<br><center><a href=' + feature.properties.url + '>USGS Details</a></center>',
            )
        },
        pointToLayer: function(feature, latlng){  // changes default icons to circles and styles accordingly
            return new L.CircleMarker(latlng, {
                radius: circleSize(feature.properties.mag),
                fillColor: getColor(feature.properties.mag),
                color: "#000",
                weight: mostRecent(feature.properties.time),
                opacity: 1,
                fillOpacity: 0.5,
            });

        }
    }).addTo(map);
    map.fitBounds(points.getBounds()); // pans to points
});

Answer 1

Make the dates variable a global variable. You're actually resetting the dates array on every function call. Refactor it to something like this

var dates = [];

function mostRecent(time) {
  dates.push(time);
  console.log(dates);
  return true
}

It should be working.