JavaScript Data Finder

A JavaScript implementation of a data finder function that uses closures to search for values within specified ranges of an array.

Problem Description

Implement the function dataFinder such that:

• It takes a single argument data, an array of integers
• It returns a new function called find
• The find function takes 3 arguments: minRange, maxRange, and value
• It searches for the value in the data array within the inclusive range [minRange, maxRange] using 0-based indexing
• Returns true if the value is found in the given range, false otherwise
• Throws an Error with message 'Invalid range' if minRange or maxRange is beyond the bounds of the array

Features

• Closure Pattern: The returned find function maintains access to the original data array
• Range Validation: Validates that indices are within array bounds
• Efficient Search: Linear search within the specified range
• Error Handling: Proper error handling for invalid ranges

Usage

Basic Example

const finder = dataFinder([1, 6, 3, 0, 2, 15, 10]);

// Search for value 10 in range [2, 4] (indices 2 through 4)
const result = finder(2, 4, 10); // Returns false
// Subarray searched: [3, 0, 2] - 10 not found

Example with Found Value

const finder = dataFinder([15, 1, 10, 5, 4, 20]);

// Search for value 4 in range [1, 4]
const result = finder(1, 4, 4); // Returns true
// Subarray searched: [1, 10, 5, 4] - 4 found at index 4

Example with Invalid Range

const finder = dataFinder([10, 1, 0, 13, 4, 15]);

try {
    const result = finder(1, 10, 13);
} catch (error) {
    console.log(error.message); // "Invalid range"
    // maxRange (10) is beyond array length (6)
}

Running the Program

From Standard Input

node dataFinder.js < input.txt

Input Format

Line 1: Space-separated integers representing the data array
Line 2: Three space-separated integers: minRange maxRange value

Sample Input

15 1 10 5 4 20
1 4 4

Sample Output

true

Test Cases

Test Case 1: Value Found

Input:

15 1 10 5 4 20
1 4 4

Output:

true

Explanation: Searching for 4 in range [1, 4] of array [15, 1, 10, 5, 4, 20]. Value 4 is found at index 4.

Test Case 2: Value Not Found

Input:

1 6 3 0 2 15 10
2 4 10

Output:

false

Explanation: Searching for 10 in range [2, 4] of array [1, 6, 3, 0, 2, 15, 10]. The subarray [3, 0, 2] does not contain 10.

Test Case 3: Invalid Range

Input:

10 1 0 13 4 15
1 10 13

Output:

Error: Invalid range

Explanation: maxRange (10) exceeds the array bounds (length 6).

Constraints

• Maximum array length: 10
• All array elements are integers
• 0-based indexing is used

Implementation Details

The dataFinder function demonstrates:

1. Closures: The inner find function has access to the data parameter
2. Validation Logic:
   • Checks if minRange < 0
   • Checks if maxRange >= data.length
   • Checks if minRange > maxRange
3. Search Algorithm: Simple linear search through the specified range
4. Error Handling: Throws Error object with specific message for invalid ranges

License

MIT License - Feel free to use this code for learning and development purposes.

Author

Created as a solution to a JavaScript coding challenge demonstrating closure patterns and array manipulation.