对于每个范围数据，请获取ID并从JSON响应中检查ID

Question

I'm trying to check any id sending with ajax and response json getting the id from json then checking if there is an id into span and then add it but is not working is always adding and adding more and more

Jquery

e.results.forEach(function(e) {
    var name = e.name;
    var id = e.id;
    if ($(".visitors span").length) {
        $('.visitors span').each(function() {
            var data_id = $(this).attr('data-id');
            if (data_id != id) {
                $(".visitors").append("<span data-id='" + id + "'>" + name + "</span>");
            }
        });
    } else {
        $(".visitors").append("<span data-id='" + id + "'>" + name + "</span>");
    }
});

Answer 1

Although I think your code is correct, but a suggestion: Instead of looping through the spans you're appending, just check if a span with a data-id exists (using CSS Attribute-Equal Selector ), if not append a new span like this:

e.results.forEach(function(e) {
    var name = e.name;
    var id = e.id;

    var $span = $(".visitors span[data-id = '" + id + "']"); // select all the spans that have the data-id equal to id
    if (!$span.length) { // if there is none
        $(".visitors").append("<span data-id='" + id + "'>" + name + "</span>"); // then add a new one
    }
});