Get json array output from php in javascript and detect if it's undefined

Question

I'm attempting to retrieve json output from a php file and output a value. Can someone enlighten me on how to detect if the value is undefined and how to access one of the values in the array?

php response:
{"myObj":[{"userid":"9000","name":"Foo"},{"userid":"1000","name":"Bar"}]}

$.ajax({
    type: 'POST',
    url: 'reply.php',
    beforeSend: function (xhr) {
        if (xhr && xhr.overrideMimeType) {
            xhr.overrideMimeType('application/json;charset=utf-8');
        }
    },
    data: {
        "action": "getmyObj"
    },
    success: function (reply) {
    if (reply.myObj.length > 0) {
        for (i = 0; i < 3; i++){
            if (typeof reply.myObj[i].name === 'undefined') {
                console.log("Undefined");
            } else {
                alert(reply.myObj[i].name);
        }
    }
});

what error you are facing? you code seems correct

Jatin Parmar
– Jatin Parmar

2021-07-05 21:21:00 +00:00
Commented Jul 5, 2021 at 21:21 — Jatin Parmar
– Jatin Parmar, Commented Jul 5, 2021 at 21:21

Dharman · Accepted Answer · 2021-07-05 21:21:07Z

1

you could replace

for (i = 0; i < 3; i++){

with

for (i = 0; i < reply.myObj.length; i++){

this way it will iterate according to how many entries there are instead of static 3 times, then u probably won´t even have to check if prop is undefined (because it is for the third iteration)

the check for the property though should be as simple as:

if (!reply.myObj[i].name) {
    console.log("Undefined");
} else {
    alert(reply.myObj[i].name);

because of the mentioned above u can be sure that reply.myObj[i] is defined

edited Jul 5, 2021 at 21:21

Dharman♦

33.9k27 gold badges106 silver badges157 bronze badges

answered Jul 5, 2021 at 21:15

john Smith

18k12 gold badges80 silver badges124 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Get json array output from php in javascript and detect if it's undefined

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related