I am trying to search any pairs key:value in an object in JavaScript, and return the sub-object it belongs to.
What I have done so far doesn’t return my object as expected and I can’t find why.
function searchSheet(obj, keyName, valName) {
let found
for (prop in obj) {
if (typeof obj[prop] == "object") {
searchSheet(obj[prop], keyName, valName);
} else {
if (prop === keyName && obj[prop] === valName) {
found = obj
console.log(found);
// found is logged correctly here
return found
// …but nothing is returned here
}
}
}
}
let sheet = {
"config": {},
"patterns": {
"id": 0,
"type": "pattern",
"startTime": 1652193369859,
"synth": "tic",
"keys": [{
"id": 1,
"type": "key",
"keyCode": 73,
"startTime": 1652193369960,
"note": 730,
"offset": "12.1"
},
{
"id": 2,
"type": "key",
"keyCode": 82,
"startTime": 1652193370371,
"note": 820,
"offset": "61.2"
}
],
"endTime": 1652193370695,
"duration": 836,
"loop": 35
}
}
console.log(
searchSheet(sheet, "keyCode", 82) // undefined
) Ian Brindley's comment is partly correct. You are discarding the return value of the recursive call. You can fix your code by changing this
if (typeof obj[prop] == "object") {
searchSheet(obj[prop], keyName, valName);
} else { //...
to this
if (typeof obj[prop] == "object") {
let objectFound = searchSheet(obj[prop], keyName, valName);
if (objectFound !== undefined) return objectFound
} else { //...
There are other approaches, particularly ones using a nested helper function.