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JS Interview Question #4

Think1s — Thu, 04 May 2023 18:52:11 +0000

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What will be the output of the following code?

for (var i = 0; i < 5; i++) { setTimeout(() => { console.log(i); }, 0); }

The output of the code will be: 5 5 5 5 5
Explanation:

For each iteration, a setTimeout method is called, which takes a callback function that logs the current value of i to the console.

However, since setTimeout is an asynchronous function, it does not execute immediately. Instead, it schedules the callback function to execute after a certain amount of time. In this case, the amount of time is set to 0, which means the callback function is scheduled to execute as soon as possible, but not immediately.

Therefore, when the for loop finishes executing, the value of i will be 5. This means that all five setTimeout functions will execute their callback function with i equal to 5, resulting in the output of 5 printed five times to the console.

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JS Interview Question #3 (Polyfill for array.flat())

Think1s — Thu, 02 Jun 2022 04:15:53 +0000

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const arr = [2, 3, 4, [5, [6, 7, [8, 9]]]];
  function flatArray(arr, depth = 1) {
    return depth > 1
      ? arr.reduce((acc, curr) => {
          acc = acc.concat(
            Array.isArray(curr) ? flatArray(curr, depth - 1) :curr);
          return acc;
        }, [])
      : arr;
  }
  console.log(flatArray(arr, Infinity));

Click here Object flattening

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JS Interview Question #2 (Accidental Global Variable)

Think1s — Tue, 22 Mar 2022 03:21:46 +0000

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Revise Accidental Global Variable concepts to answer this questions.

What is the output the following code?

function getNumber() {
        var a = b = 2;
        a++;
        return a;
      }
      console.log(typeof a);
      console.log(typeof b);

To know the answer click here

What is the output the following code?

 function getNumber() {
        var a = b = 2;
        a++;
        return a;
      }
      getNumber();
      console.log(typeof a);
      console.log(typeof b);

To know the answer click here

JS Interview Question #1 (Group Anagrams)

Think1s — Sun, 20 Mar 2022 03:30:12 +0000

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What is Anagram?
According to wikipedia Anagram is a word, phrase, or name formed by rearranging the letters of another.
Ex: Elbow and below

let groupAnagramsObj = {};
  for (let i of distinctArrSet) {
    let groupArr = sortedArr.reduce((acc, curr, index) => {
      if (curr == i) {
        acc.push(index);
      }
      return acc;
    }, []);
    groupAnagramsObj[i] = groupArr;
  }

  // console.log(groupAnagramsObj)
  // { "below": [ 0, 1 ], "ceersu": [ 2, 3 ], "act": [ 4, 5, 6 ] }

  let anagramsGroup = [];
  for (let i in groupAnagramsObj) {
    anagramsGroup.push(groupAnagramsObj[i].map((item) => arr[item]));
  }
  return anagramsGroup;
};
console.log(
  groupAnagrams(["elbow", "rescue", "cat", "secure", "act", "below", "tac"])
);

// [["below","elbow"],["secure","rescue"],["cat","act","tac"]]

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