js sort（）自定义函数如何传递更多参数？

Question

I have an array of objects i need to sort on a custom function, since i want to do this several times on several object attributes i'd like to pass the key name for the attribute dinamically into the custom sort function:

function compareOnOneFixedKey(a, b) {
    a = parseInt(a.oneFixedKey)
    b = parseInt(b.oneFixedKey)
    if (a < b) return -1
    if (a > b) return 1
        return 0
}

arrayOfObjects.sort(compareByThisKey)

should became something like:

function compareOnKey(key, a, b) {
    a = parseInt(a[key])
    b = parseInt(b[key])
    if (a < b) return -1
    if (a > b) return 1
        return 0
}
arrayOfObjects.sort(compareOn('myKey'))

Can this be done in a convenient way? thanks.

Answer 1

You may add a wrapper:

function compareOnKey(key) {
    return function(a, b) {
        a = parseInt(a[key], 10);
        b = parseInt(b[key], 10);
        if (a < b) return -1;
        if (a > b) return 1;
        return 0;
    };
}

arrayOfObjects.sort(compareOnKey("myKey"));

Answer 2

You would need to partially apply the function, eg using bind :

arrayOfObjects.sort(compareOn.bind(null, 'myKey'));

Or you just make compareOn return the actual sort function, parametrized with the arguments of the outer function (as demonstrated by the others).

Answer 3

Yes, have the comparator returned from a generator which takes a param which is the key you want

function compareByProperty(key) {
    return function (a, b) {
        a = parseInt(a[key], 10);
        b = parseInt(b[key], 10);
        if (a < b) return -1;
        if (a > b) return 1;
        return 0;
    };
}
arrayOfObjects.sort(compareByProperty('myKey'));

compareByProperty('myKey') returns the function to do the comparing, which is then passed into .sort

Answer 4

 const objArr = [{ name: 'Z', age: 0 }, { name: 'A', age: 25 }, { name: 'F', age: 5 }] const sortKey = { name: 'name', age: 'age' } const sortArr = (arr, key) => { return arr.sort((a, b) => { return a[key] < b[key] ? -1 : a[key] > b[key] ? 1 : 0 }) } console.log("sortKey.name: ", sortArr(objArr, sortKey.name)) console.log("sortKey.age: ", sortArr(objArr, sortKey.age))