Creating an array using comparison operator?

JavaScript
1

Tell us what’s happening:
This else if statement has my brain scrambled. I am confused because it is using a comparison operator but at the same time… creating an array which doesnt make sense to me. Here’s the code:

else if(prop === “tracks”) {
collection[id][prop] = collection[id][prop] || ;
collection[id][prop].push(value);
}

Can someone help me write a less complex statement? I feel like I need some other way to wrap my head around this. This exercise in general seemed to go from 0-100 so im trying to understand!

Thanks for any help!!

Your code so far


var collection = {
2548: {
  album: "Slippery When Wet",
  artist: "Bon Jovi",
  tracks: [
    "Let It Rock",
    "You Give Love a Bad Name"
  ]
},
2468: {
  album: "1999",
  artist: "Prince",
  tracks: [
    "1999",
    "Little Red Corvette"
  ]
},
1245: {
  artist: "Robert Palmer",
  tracks: [ ]
},
5439: {
  album: "ABBA Gold"
}
};

// Only change code below this line
function updateRecords(id, prop, value) {
if(value === "") {
  delete collection[id][prop];
}
else if(prop === "tracks") {
  collection[id][prop] = collection[id][prop] || [];
  collection[id][prop].push(value);
} else {
  collection[id][prop] = value;
}

return collection;
}

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.89 Safari/537.36.

Challenge: Record Collection

Link to the challenge:

2

this is a comparison operator, ===

here = is an assignment operator
and the assigned value is collection[id][prop] || []
what happens here is that if collection[id][prop] is truthy, than it is what is assigned, effectively changing nothing, if instead it is falsy, then the expression after the OR operator is assigned, so the empty array

try reading this:

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