Json获取Javascript中的所有嵌套元素

Question

I have a Json structure that I need to run some unit tests on. The structure looks like the following.

{
tracks:{
    4j38f8-4j39fj-3j4j3j:{
        name:"my video track",
        mediaType:"VIDEO"
    },
    280248-248244-ttr24:{
        name:"my audio track",
        mediaType:"AUDIO"
    },
    280248-248244-ttr24:{
        name:"my audio track",
        mediaType:"AUDIO"
    }
}

In javascript I have the following code.

var data = JSON.parse(jsonFile.json);
if(data.4j38f8-4j39fj-3j4j3j.mediaType == "VIDEO")
{
    do something
}
else
{
    do something else
}
if(data.4j38f8-4j39fj-3j4j3j.mediaType == "VIDEO")
{
    do something
}
else
{
    do something else
}
if(data.4j38f8-4j39fj-3j4j3j.mediaType == "VIDEO")
{
    do something
}
else
{
    do something else
}

However, I do not know how many tracks there will be, and I want to something different depending on what type of track it is. This leads me to believe that I should iterate through the object. Yet because it is not an array, I need to get the key of whatever the next object is inside of a loop. My question is how can I do this?

For element in tracks
{
    if element.mediaType = video
    {
        do one thing
    }
    else
    {
        do another thing
    }
}

Answer 1

By using a for..in structure:

for (var key in data.tracks) {
    if (data.tracks.hasOwnProperty(key)) {
        if (data.tracks[key].mediaType === 'VIDEO') {
            // do one thing
        } else {
            // do another thing
        }
    }
}