Sorting one array by another array and appending unknown missing items

Question

Say I have an order which is just an ordered list that references the array of objects with a sectionId. I'd like the items missing from the order list to be appended to the end of the sorted array. However my example below the missing items are put at the top of the list - help appreciated!

const orders = [
[
    "one", 
    "two",
    "three",
],
[
    "two",
    "three",
    "one", 
],
[
    "three",
    "one", 
    "two",
]
]

const sections = {
0: [
    {
        "sectionId": "a"
    }, 
    {
        "sectionId": "two"
    },
    {
        "sectionId": "z"
    },
    {
        "sectionId": "three"
    },
    {
        "sectionId": "one"
    }, 
],
1: [
    {
        "sectionId": "a"
    },
    {
        "sectionId": "three"
    },
    {
        "sectionId": "one"
    }, 
    {
        "sectionId": "z"
    }, 
    {
        "sectionId": "two"
    },
], 
2: [
    {
        "sectionId": "z"
    },
    {
        "sectionId": "a"
    }, 
    {
        "sectionId": "two"
    },
    {
        "sectionId": "three"
    },
    {
        "sectionId": "one"
    }, 
]
}

const outcomes = {
0: [
    {
        "sectionId": "one"
    }, 
    {
        "sectionId": "two"
    },
    {
        "sectionId": "three"
    },
    {
        "sectionId": "a"
    },
    {
        "sectionId": "z"
    }, 
],
1: [
    {
        "sectionId": "two"
    },
    {
        "sectionId": "three"
    },
    {
        "sectionId": "one"
    },
    {
        "sectionId": "a"
    },
    {
        "sectionId": "z"
    }, 
],
2: [
    {
        "sectionId": "three"
    },
    {
        "sectionId": "one"
    }, 
    {
        "sectionId": "two"
    },
    {
        "sectionId": "z"
    },
    {
        "sectionId": "a"
    }, 
],
}

// function
const generateOrderedSections = (sections, order) => {
return sections.sort((a, b) => {
    const aIndex = order.indexOf(a.sectionId)
    const bIndex = order.indexOf(b.sectionId)
    const sortOrder = aIndex > 0 && aIndex > bIndex ? 1 : -1
    // console.log(aIndex, a.sectionId, bIndex, b.sectionId, sortOrder)
    return sortOrder;
})
}

// test cases
orders.forEach((order, index) => {
const section = sections[index]
const test = generateOrderedSections(section, order)
const result = JSON.stringify(test)
const outcome = JSON.stringify(outcomes[index])

if (result === outcome) {
    console.log(index, 'passed')
} else {
    console.log('-------------')
    console.log('failed')
    console.log('-------------')
    console.log('expected')
    console.log(outcomes[index])
    console.log('\nresult')
    console.log(test)
}
})

why comes 'z' before 'a' in thei first part?

Nina Scholz
– Nina Scholz

2019-11-29 12:30:01 +00:00
Commented Nov 29, 2019 at 12:30 — Nina Scholz
– Nina Scholz, Commented Nov 29, 2019 at 12:30
Fixing the test case now thanks

azz0r
– azz0r

2019-11-29 12:31:47 +00:00
Commented Nov 29, 2019 at 12:31 — azz0r
– azz0r, Commented Nov 29, 2019 at 12:31

Nina Scholz · Accepted Answer · 2019-11-29 12:42:20Z

1

You could add one tho the index, and this yields zero (for unknow indices) and take a default value of a large number to sort this items to the end.

const
    orders = [["one", "two", "three"], ["two", "three", "one"], ["three", "one", "two"]],
    sections = { 0: [{ sectionId: "a" }, { sectionId: "two" }, { sectionId: "z" }, { sectionId: "three" }, { sectionId: "one" }], 1: [{ sectionId: "a" }, { sectionId: "three" }, { sectionId: "one" }, { sectionId: "z" }, { sectionId: "two" }], 2: [{ sectionId: "z" }, { sectionId: "a" }, { sectionId: "two" }, { sectionId: "three" }, { sectionId: "one" }] },
    outcomes = { 0: [{ sectionId: "one" }, { sectionId: "two" }, { sectionId: "three" }, { sectionId: "a" }, { sectionId: "z" }], 1: [{ sectionId: "two" }, { sectionId: "three" }, { sectionId: "one" }, { sectionId: "a" }, { sectionId: "z" }], 2: [{ sectionId: "three" }, { sectionId: "one" }, { sectionId: "two" }, { sectionId: "z" }, { sectionId: "a" }] },
    generateOrderedSections = (sections, order) => {
        return sections.sort((a, b) =>
            ((order.indexOf(a.sectionId) + 1) || Number.MAX_VALUE) -
            ((order.indexOf(b.sectionId) + 1) || Number.MAX_VALUE)
        );
    };

// test cases
orders.forEach((order, index) => {
    const section = sections[index]
    const test = generateOrderedSections(section, order)
    const result = JSON.stringify(test)
    const outcome = JSON.stringify(outcomes[index])

    if (result === outcome) {
        console.log(index, 'passed')
    } else {
        console.log('-------------')
        console.log('failed')
        console.log('-------------')
        console.log('expected')
        console.log(outcomes[index])
        console.log('\nresult')
        console.log(test)
    }
})

.as-console-wrapper { max-height: 100% !important; top: 0; }

edited Nov 29, 2019 at 12:42

answered Nov 29, 2019 at 12:33

Nina Scholz

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3 Comments

azz0r Over a year ago

Thanks, I seem to get all results ordered the same as: one, two, three unfortunately

Nina Scholz Over a year ago

sorry, i missed some parentheses.

azz0r Over a year ago

Thank you :) Great job makes sense and is concise

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