Javascript Interview Question:Search keyword in Nexted Array

Problem Statement:

Given a nexted array of multiple levels find if a value exists in that

nexted array. E.g.For

const nextedArray = [0, 1, [2, [3, [4, 5]]]];

if we pass 5 to be found then it should return true.if we pass 7 it should

return false.

Solution:

function findInNextedArray(nextedArray, valueTobeFound) {

function flattenNextedArray(nextedArray) {

let output = [];

for (let i = 0; i < nextedArray.length; i++) {

if (Array.isArray(nextedArray[i])) {

let intermediateResult = flattenNextedArray(nextedArray[i]);

output = output.concat(intermediateResult);

} else {

output.push(nextedArray[i]);

}

}

return output;

}

let flattenedNextedArray = flattenNextedArray(nextedArray);

return flattenedNextedArray.includes(valueTobeFound);

}

//driver code

const nextedArray = [0, 1, [2, [3, [4, 5]]]];

const valueTobeFound = 5;

let foundInArray = findInNextedArray(nextedArray, valueTobeFound);

let response = foundInArray ? "found" : "not found";

console.log(`${valueTobeFound} is ${response} in given nexted array`);

Output:

5 is found in given nexted array

Note:

Their is inbuild flat method on array that also give you flatten array.

Using that method we can do same thing as follows.

const nextedArray = [0, 1, [2, [3, [4, 5]]]];

const valueTobeFound = 5;

let response = nextedArray.flat(Infinity).includes(valueTobeFound) ?

"found":"not found"

console.log(`${valueTobeFound} is ${response} in given nexted array`);

Output:

5 is found in given nexted array