Reduce

Calls the specified callback function for all the elements in an object. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function

Functional programming

• Typing:

<R = O[keyof O]>(handler: (previousValue: R, currentValue: O[keyof O], currentKey: keyof O) => R, initial?: R | undefined) => R | undefined

• Example:

import objectAsArray from "object-as-array";

export default function example() {
    
    const obj = objectAsArray({
        I : 1,
        V : 5,
        X : 10,
        L : 50,
        C : 100,
        D : 500,
        M : 1000
    });

    return obj.reduce((p, v) => p + v, 334);

    // Result: 2000

}

Modular programming

• Typing:

<O extends object, R = O[keyof O]>(object: O, handler: (previousValue: R, currentValue: O[keyof O], currentKey: keyof O) => R, initial?: R | undefined) => R | undefined

• Example:

import reduce from "object-as-array/reduce";

export default function example() {
    
    const obj = {
        I : 1,
        V : 5,
        X : 10,
        L : 50,
        C : 100,
        D : 500,
        M : 1000
    };

    return reduce(obj, (p, v) => p + v, 334);

    // Result: 2000

}