Sort an array of object by a property (with custom order, not alphabetically)

Question

I would like to get your help about this little problem.

I have like to order this array depending on the code value but not in alphabetical order. (I specified this in bold but got eventually flagged anyway, people don't even care about reading the question)

For example I would like to have all the green objects, then all the blue ones and then all the red ones. What is the best way to do that?

[
    { code: "RED", value: 0},
    { code: "BLUE", value: 0},
    { code: "RED", value: 0},
    { code: "GREEN", value: 0},
    { code: "BLUE", value: 0},
    { code: "RED", value: 0},
    { code: "GREEN", value: 0},
    { code: "BLUE", value: 0}
]

Is it possible to do that with the sort function? What would the condition be in that case?

Answer 1

You could take an object for the wanted order.

var array = [{ code: "RED", value: 0 }, { code: "BLUE", value: 0 }, { code: "RED", value: 0 }, { code: "GREEN", value: 0 }, { code: "BLUE", value: 0 }, { code: "RED", value: 0 }, { code: "GREEN", value: 0 }, { code: "BLUE", value: 0 }],
    order = { GREEN: 1, BLUE: 2, RED: 3 };
    
array.sort(function (a, b) {
    return order[a.code] - order[b.code];
});

console.log(array);

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

For unknow colors/values, you could use a default value with

• 0, for sorting to top or
• Infinity or as some suggest because of the ability for caculating Number.MAX_VALUE for sorting to the end,
• or any other value for sorting inbetween the other groups.

At last you could sort the special treated items with an other sorting part, chained with logical OR ||.

var array = [{ code: "YELLOW", value: 0 }, { code: "BLACK", value: 0 }, { code: "RED", value: 0 }, { code: "BLUE", value: 0 }, { code: "RED", value: 0 }, { code: "GREEN", value: 0 }, { code: "BLUE", value: 0 }, { code: "RED", value: 0 }, { code: "GREEN", value: 0 }, { code: "BLUE", value: 0 }],
    order = { GREEN: 1, BLUE: 2, RED: 3, default: Infinity };
    
array.sort(function (a, b) {
    return (order[a.code] || order.default) - (order[b.code] || order.default) || a.code.localeCompare(b.code);
});

console.log(array);

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