CODEWITHSUNDEEP
jquery
Acubi
Acubi

Reputation: 2783

bug on result of success function is "null" in Jquery ajax

When result of success function is "null", the message still display "have value".

Can anyone help me, many thanks!

$(document).ready(function () {
    setInterval(function () {
        $.ajax({
            url: "getData.php",
            success: function (result) {
                if (result.length == 0) {
                    $("#rlt").append("no value");
                } else {
                    $("#rlt").append("have value");
                }
            },
            dataType: "json"
        });
    }, 2000);
});

<p id="rlt"></p>

Upvotes: 1

Views: 234

Answers (1)

RightSaidFred
RightSaidFred

Reputation: 11327

Instead of the value null, you're probably sending the string "null", which will not have a zero length:

Test for the string itself.

if (result === "null") {
    $("#rlt").append("no value");
} else {
    $("#rlt").append("have value");
}

If you're anticipating an actual null value in the response, then you wouldn't want to use .length, because you'll get a TypeError.

By the way, I don't think a standalone "null" or null is valid JSON, but the native parsers don't seem to mind it.

Upvotes: 2

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