Obtain values that match from several conditions on a list in javascript - list

Question

I'm trying to obtain a list from a list in Javascript.
This is the list:
const cars = [
{
id: 1,
brand: "Mercedes Benz",
properties: [
{
property: "Mechanical",
value: 2,
},
{
property: "Chemical",
value: 2,
},
{
property: "Pressure",
value: 3,
}],
},
{
id: 2,
brand: "BMW",
properties: [
{
property: "Mechanical",
value: 5,
},
{
property: "Chemical",
value: 3,
},
{
property: "Pressure",
value: 6,
}],
}
]
I need the cars which match some properties property with a value greater than X, Y
For example, I want the cars which Mechanical properties have a value greater than 3 and a Pressure greater than 4. In that case I'll obtain the complete object with id 2.
Does anyone have an idea? That is having me a hard time
Tip: I paste it on a Node REPL ;)
This is what I tried but I obtain nothing:
cars.filter(car => car.properties.some((p1, p2) => {return ((p1.property === "Mechanical" && p1.value > 3) && (p2.property === "Pressure" && p2.value > 4))}))
Thanks in advance

Answer 1

You need to iterate all items and check each one for it's relevant condition, and if all items pass, return true. In your case you are checking each item for all conditions, and since no item's property can have both "Mechanical" and "Pressure" values at the same time, all fail.
When an array needs to pass all conditions, you should use Array.every() that will only return true, if all iterated items would return true.
To make this more generic, we can store the conditions as functions in an object or a Map. If there is a condition function for this property, we'll use the function to check the value. If not, we can return true immediately.
Note: this answer uses Optional chaining (?.) and the Nullish coalescing operator (??) to return true if the predicate doesn't exist. If your running environment doesn't support this operators replace the line with predicate[property] ? predicate[property](value) : true (see 2nd example).
const fn = (predicate, cars) =>
cars.filter(car => car.properties.every(({ property, value }) =>
predicate[property]?.(value) ?? true
))
const cars = [{"id":1,"brand":"Mercedes Benz","properties":[{"property":"Mechanical","value":2},{"property":"Chemical","value":2},{"property":"Pressure","value":3}]},{"id":2,"brand":"BMW","properties":[{"property":"Mechanical","value":5},{"property":"Chemical","value":3},{"property":"Pressure","value":6}]}]
const predicate = {
Mechanical: value => value > 3,
Pressure: value => value > 4,
}
const result = fn(predicate, cars)
console.log(result)
Or using a ternary:
const fn = (predicate, cars) =>
cars.filter(car => car.properties.every(({ property, value }) =>
predicate[property] ? predicate[property](value) : true
))
const cars = [{"id":1,"brand":"Mercedes Benz","properties":[{"property":"Mechanical","value":2},{"property":"Chemical","value":2},{"property":"Pressure","value":3}]},{"id":2,"brand":"BMW","properties":[{"property":"Mechanical","value":5},{"property":"Chemical","value":3},{"property":"Pressure","value":6}]}]
const predicate = {
Mechanical: value => value > 3,
Pressure: value => value > 4,
}
const result = fn(predicate, cars)
console.log(result)