gistfile1.js

/* Original */

var setIcon = function (evt) {
    var base = "http://incidents.slocountyfire.org/static/img/";
    if (evt.properties.category === "Medical") {
        evt.layer.options.icon = new L.Icon(base + "m-marker.png");
    } else if (evt.properties.category === "Fire") {
        evt.layer.options.icon = new L.Icon(base + "f-marker.png");
    } else if (evt.properties.category === "Hazard") {
        evt.layer.options.icon = new L.Icon(base + "h-marker.png");
    } else if (evt.properties.category === "Public Assist") {
        evt.layer.options.icon = new L.Icon(base + "pa-marker.png");
    } else if (evt.properties.category === "Law Enforcement") {
        evt.layer.options.icon = new L.Icon(base + "le-marker.png");
    } else {
        evt.layer.options.icon = new L.Icon(base + "o-marker.png");
    }
};

/* Switch */

var setIcon = function (evt) {
    var base = "http://incidents.slocountyfire.org/static/img/", marker;
    switch (evt.properties.category) {
        case "Medical":
            marker = "m-marker.png";
            break;
        case "Fire":
            marker = "f-marker.png";
            break;
        case "Hazard":
            marker = "h-marker.png";
            break;
        case "Public Assist":
            marker = "pa-marker.png";
            break;
        case "Law Enforcement":
            marker = "le-marker.png";
            break;
        default:
            marker = "o-marker.png";
    }
    evt.layer.options.icon = new L.Icon(base + marker);
};

/* Improve if-then */

var setIcon = function (evt) {
    var base = "http://incidents.slocountyfire.org/static/img/", 
        category = evt.properties.category, marker;
    if (category === "Medical") {
        marker = "m-marker.png";
    } else if (category === "Fire") {
        marker = "f-marker.png";
    } else if (category === "Hazard") {
        marker = "h-marker.png";
    } else if (category === "Public Assist") {
        marker = "pa-marker.png";
    } else if (category === "Law Enforcement") {
        marker = "le-marker.png";
    } else {
        marker = "o-marker.png";
    }
    evt.layer.options.icon = new L.Icon(base + marker);
};