Can you explain the purpose of the filters within this function and elaborate on how exactly we are achieving the return value?

Question

Can you explain the purpose of the filters within this function and elaborate on how exactly we are achieving the return value?

Can you explain the functioning of the code snippet provided below?

function areSimilar(a, b) {
const ad = a.filter((v,i)=>v!=b[i])
const bd = b.filter((v,i)=>v!=a[i])
return ad.length == 0 || (ad.length == 2 && ad.join('') == 
bd.reverse().join(''))
}

javascript

Answer 1

Answer №1

Filtering is a powerful concept in programming, especially when working with arrays. By using the filter method, you can create a new array based on specific conditions defined by a predicate function. This results in a more refined and targeted array that only contains elements meeting those conditions. For more details, check out: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter.

In the example of a.filter((v, i) => v != b[i]), each element in array a is compared to the corresponding element in array b. If they are not equal, the element is kept in the resulting array ad. The same logic applies to bd.

If ad ends up empty, it means there are no differences between the two arrays a and b, leading to a return value of true. The definition of 'similar' here revolves around identifying arrays that are either identical or differ by one pair of swapped elements.

When there's a single pair of swapped elements present, both ad and bd will contain exactly two elements. By flipping the order of elements in

bd</code and comparing it to <code>ad

, the author confirms whether this swapping condition holds true.

For instance:

let a = [1, 2, 3, 4]
let b = [1, 4, 3, 2]

In this case, ad == [2, 4] and bd == [4, 2], leading to the comparison

ad.join('') == bd.reverse().join('')

.

Note: Joining the elements together allows for direct value comparisons, such as "24" === "24".

Answer 2

Filtering is a powerful concept in programming, especially when working with arrays. By using the filter method, you can create a new array based on specific conditions defined by a predicate function. This results in a more refined and targeted array that only contains elements meeting those conditions. For more details, check out: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter.

In the example of a.filter((v, i) => v != b[i]), each element in array a is compared to the corresponding element in array b. If they are not equal, the element is kept in the resulting array ad. The same logic applies to bd.

If ad ends up empty, it means there are no differences between the two arrays a and b, leading to a return value of true. The definition of 'similar' here revolves around identifying arrays that are either identical or differ by one pair of swapped elements.

When there's a single pair of swapped elements present, both ad and bd will contain exactly two elements. By flipping the order of elements in

bd</code and comparing it to <code>ad

, the author confirms whether this swapping condition holds true.

For instance:

let a = [1, 2, 3, 4]
let b = [1, 4, 3, 2]

In this case, ad == [2, 4] and bd == [4, 2], leading to the comparison

ad.join('') == bd.reverse().join('')

.

Note: Joining the elements together allows for direct value comparisons, such as "24" === "24".

Can you explain the purpose of the filters within this function and elaborate on how exactly we are achieving the return value?

Answer №1

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