Snippet-ReduceOneOfEach

Reduce Function that takes an array and returns an array with one of each item.

Un-nested Array

    // Example:
    let myArray = ['a', 'b', 'b', 'c'];

    let newArry = myArray.reduce((accumulator, currentVal) => {
        // IF in the accumulator the item exists then return accumulator unchanged
        // IF item does not exist then push to accumulator then return
        if(accumulator.indexOf(currentVal) === -1){
            accumulator.push(currentVal); // NOTE: push returns the lenght of an array, so don't prefix return here.
        }
        return accumulator;
    }, []);

    console.log('newArry: ', newArry ); // ['a', 'b', 'c'];

Nested Array

    // Example:
    let myArray = [
        {
            item1: 'a',
            item2: 1
        },
        {
            item1: 'b',
            item2: 1
        },
        {
            item1: 'b',
            item2: 1
        },
        {
            item1: 'c',
            item2: 1
        },
        {
            item1: 'c',
            item2: 1
        }
    ];

    let newArry = myArray.reduce((accumulator, currentVal) => {
    // IF in the accumulator the item exists then return accumulator unchanged
    // IF item does not exist then push to accumulator then return
        if(accumulator.indexOf(currentVal.item1) === -1){
            accumulator.push(currentVal.item1); // NOTE: push returns the lenght of an array, so don't prefix return here.
        }
        return accumulator;
    }, []);

    console.log('newArry: ', newArry ); // ['a', 'b', 'c'];