TypeScript example class for array flattener

arraysquasher.ts

// Flatten nested arrays of numbers into a single-dimension array of numbers
// e.g. [0, 1, [2, 3, [4, 5]]] => [0, 1, 2, 3, 4, 5]
class ArraySquasher {
  
  // Private method - Recursively flatten array
  private static recurse(arr: Array<any>): Array<number> {
    
    // Initialize result and process array
    var result = [];
    for (var i = 0, ii = arr.length; i != ii; ++i) {
      
      var x = arr[i];
      if (Array.isArray(x)) {
        // Continue recursively processing array
        result = result.concat(ArraySquasher.recurse(x));
      }
      else if (typeof(x) == 'number') {
        // Push the number onto the array
        result.push(x);
      }
    }
    
    // Return the flattened array component
    return result;
  }
  
  // Public method - Take input array and return flattened single-dim array
  public static flatten(arr: Array<any>): Array<number> {
    
    // Kick off array processing and return the result
    return [].concat(ArraySquasher.recurse(arr));
  }  
}