Best way to restructure nested if statements

Question

I have the following code:

const config = {
    key1: {
        outlier: 'outlier1'
    },
    key2: {
        test: 'test'
    },
    key3: {
        outlier: 'outlier3'
    }
}

const finalArr = [];

Object.keys(config).forEach((key) => {
    const obj = config[key];
    // How to make this if/if/else structure cleaner?
    if (obj.outlier) {
        if (doSomeWithOutlier(obj.outlier)) {
            finalArr.push(obj);
        }
    }else {
        finalArr.push(obj);
    }
});

Is there a cleaner way to do the above following? It seems like I am nesting the if/if stamenets and else statements to much and duplicating finalArr.push(obj) code.

Answer 1

You could use:

    if ((obj.outlier && doSomeWithOutlier(obj.outlier)) || !obj.outlier) {
        finalArr.push(obj);
    }

However, I think your structure is easier to read.

You can also loop over Object.values(config) rather than the keys, so you don't need the extra step of const obj = config[key];.

Answer 2

Alternative:

if (obj.outlier && !doSomeWithOutlier(obj.outlier))
  return;

finalArr.push(obj);

Answer 3

The others showed you how to handle the if/if/else as a single condition to make the code shorter, using Object.values() and .reduce would help to make the code even shorter:

const finalArr = Object.values(config).reduce((arr, el) =>
el.outlier && doSomeWithOutlier(el.outlier) ? [...arr, el] : arr,
[]);

If you want to perform some operation in case .outlier is not present you just change the last statement of ternary operator.

Answer 4

Hope this'll inspire your solution,

const newConfig = Object.entries(config).reduce((accum, [key, value], idx) => {
    //  const truthsy = doSomethingWithOutliner(value)
  
    return [...accum, idx%2 === 0 ? 'even' : 'odd']
}, [])

ps: It's not a good practice to name your variables like config and finalArray. Also, you are pushing the same (obj) no matter what.

refer: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce