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Array Flattening

Certification: Basic Level Accuracy: 25% Submissions: 4 Points: 5

Write a JavaScript program to flatten a single-level nested array. Given an array that contains other arrays as elements, convert it into a single flat array containing all the individual elements. For example, [1, [2, 3], 4, [5, 6]] should become [1, 2, 3, 4, 5, 6].

Example 1
    
      
  • Input: arr = [1, [2, 3], 4, [5, 6]]
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  • Output: [1, 2, 3, 4, 5, 6]
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  • Explanation: 
    • The array contains elements: 1, [2, 3], 4, [5, 6]. 
    • Element 1 is a number, keep it as is. 
    • Element [2, 3] is an array, extract 2 and 3. 
    • Element 4 is a number, keep it as is. 
    • Element [5, 6] is an array, extract 5 and 6. 
    • Final flattened array: [1, 2, 3, 4, 5, 6].
    •
Example 2
    
      
  • Input: arr = [10, [20], [30, 40], 50]
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  • Output: [10, 20, 30, 40, 50]
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  • Explanation: 
    • The array contains elements: 10, [20], [30, 40], 50. 
    • Element 10 is a number, keep it as is. 
    • Element [20] is an array with one element, extract 20. 
    • Element [30, 40] is an array, extract 30 and 40. 
    • Element 50 is a number, keep it as is. 
    • Final flattened array: [10, 20, 30, 40, 50].
    •
Constraints
    
      
  • 1 ≤ arr.length ≤ 1000
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  • Array elements can be numbers or single-level nested arrays
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  • No deep nesting (only one level of nesting allowed)
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  • Time Complexity: O(n) where n is total number of elements
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  • Space Complexity: O(n) for the result array
    •
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Solution

Solution Hints

    
      
  • Create an empty result array to store flattened elements
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  • Iterate through each element of the input array
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  • Check if the current element is an array using Array.isArray()
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  • If it's an array, iterate through its elements and add them to result
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  • If it's not an array, directly add the element to result
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  • Return the flattened result array
    •

Steps to solve by this approach:

 Step 1: Initialize an empty result array to store the flattened elements.
 Step 2: Start iterating through each element of the input array.
 Step 3: For each element, check if it is an array using Array.isArray() method.
 Step 4: If the element is an array, iterate through all its sub-elements.
 Step 5: Add each sub-element to the result array using push() method.
 Step 6: If the element is not an array, directly add it to the result array.
 Step 7: Continue this process for all elements and return the final flattened array.

Submitted Code :