jquery ajax 中实现给变量赋值

<script src="/jquery.min.js"></script>
<script type="text/javascript">
var icon = '/images/location.png';
$.ajax({
    type: 'post',
    async: false,
    url: '{:url("getIcon")}',
    data: {type_id: type_id},
    dataType: 'json',
    success: function (data) {
        if(data != null){
            icon = data;
        }
    }
});
console.log(icon);
</script>