JSON error, half of the variable are undefined

Question

So I have a problem with my JSON. It throws me an undefined. What makes it strange is that it recognizes my first variable.

Here are the codes to make it clear.

JSON

{"Comics":[
{"comic" : 
    {
    "src":"Pictures/Comics/dw.jpg",
    "descr":"Doctor Who has a nice tv show."
    }
},
{"comic" : 
    {
    "src":"Pictures/Comics/spi.jpg",
    "descr":"Spider man is a nice comic \
            The main spider-man comic \
            ended with Peter Parker's \
            death."
    }
},
{"comic" : 
    {
    "src":"Pictures/Comics/gg.jpg",
    "descr":"Power puff girls also has a \
            nice tv show .   \
            You should try watching it."
    }
},
{"comic" : 
    {
"src":"Pictures/Comics/v.jpg",
"descr":"V fo Vendeta is a nice  \
            graphical volume written by\
            Allan Moor who also wrote \
            Watchmen. Those books had a movie."
    }
}


 ]
}

Here is my Javascript

var arrI = new Array(4);
var arrD = new Array(4);

var x = new XMLHttpRequest;
x.onload = function(){
    if(x.status == 200){
    var txt = JSON.parse(x.responseText);
for(var g = 0; g<txt.Comics.length; g++){
        arrI[g] = txt.Comics[g].comic.src;
        arrD[g] = txt.Comics[g].comic.descr;
        alert(arrD[g]);
    }
    }
}

x.open("GET",'Ajax/ImgCom.json', true);
x.send(null);

The strange part is that the arrI[g] = txt.Comics[g].comic.src; is ok. If I alert it, it gives me the src. But the desc is not. It alerts me undefined. I don't understand why, after all, they both have the good path.

I tried to correct myself with https://jsonlint.com. It told me:

Error: Parse error on line 5:
....jpg",               "descr": 'Doctor Who has a ni

----------------------^

Expecting 'STRING', 'NUMBER', 'NULL', 'TRUE', 'FALSE', '{', '[', got 'undefined'

I then tried to change the " of the desc to ', but it didn't work.

Finally, I also tried the ...=txt.Comics[g].comic[desc] notation, but it still gave e undefined.

I corrected myself, I didn't found any typo. Maybe there are.

Thank you for your time.

How are you generating your JSON? You should use standard JSON encoding functions in your favorite environment. Never try to generate JSON yourself. — jcaron, May 14 '17 at 22:39

score 1 · Accepted Answer · edited May 23 '17 at 12:18

1

You can't split your String values over multiple lines like that in JSON.

{
"src":"Pictures/Comics/spi.jpg",
"descr":"Spider man is a nice comic \
        The main spider-man comic \
        ended with Peter Parker's \
        death."
}

Needs to be changed to this...

{
"src": "Pictures/Comics/spi.jpg",
"descr": "Spider man is a nice comic The main spider-man comic ended with Peter Parker's death."
}

You will need to change some of your other entries too. See here Multiline strings in JSON

edited May 23 '17 at 12:18

Community

1
1

answered May 14 '17 at 22:30

Thomas Powell

115
1
12

Thanks, It worked just fine in one line. Also, according to what I've understood from your link, there is a way to do a multiline string. It doesn't matter now, but it I would have wanted to do so, how could I have done? – ATrashInTheWorld May 14 '17 at 23:20
`JSON` does not support multiline string values. If you are wanting the value to render on multiple lines you can encode newline '`\n`' characters into the string value. If you are wanting the value in the `JSON` document to appear across multiple lines for readability you could change the value type to an `Array` of `String`s and then join them in your code. – Thomas Powell May 15 '17 at 09:04

JSON error, half of the variable are undefined

1 Answers1