JavaScript Coding Exercise on Step Shapes

In this blog post, we’ll tackle an interesting coding exercise that involves creating step shapes using the # character in JavaScript. This challenge is perfect for beginners looking to strengthen their understanding of loops, string manipulation, and basic algorithm design.

Problem Statement

Write a function that accepts a positive integer N and prints a step shape with N levels using the # character. Each step should have spaces on the right-hand side to form a right-aligned shape. Here are a few examples:

steps(2);
// Output:
// '# '
// '##'

steps(3);
// Output:
// '#  '
// '## '
// '###'

steps(4);
// Output:
// '#   '
// '##  '
// '### '
// '####'

Step-by-Step Solution

Let’s break down the solution to this problem. We need a function that can construct each step and ensure that it has the correct number of # characters followed by spaces.

Initial Approach

Here’s a basic solution that uses two functions: one for looping through each level (steps) and another for constructing the individual step strings (print).

function steps(n) {
  for (let i = 1; i <= n; i++) {
    console.log(print(i, n));
  }
}

function print(c, n) {
  let str = '';

  // Construct the step with `c` number of `#`
  for (let j = 0; j < c; j++) {
    str += '#';
  }

  // Add spaces until the length is `n`
  while (str.length < n) {
    str += ' ';
  }

  return str;
}

Explanation:

1. Looping Through the Levels (steps Function):

• We loop from 1 to N, where i represents the current step level.
• For each level, we generate the corresponding step string using the print function and log it to the console.

1. Constructing Each Step (print Function):

• We first add c number of # characters to a string.
• We then add spaces to the right until the string’s length equals n.

Optimizing the Solution

While the initial approach works, we can simplify it using the built-in padEnd() method in JavaScript. This method pads the current string with a given character until the string reaches the specified length.

Here’s the optimized version:

function steps(n) {
  for (let i = 1; i <= n; i++) {
    console.log(print(i, n));
  }
}

function print(c, n) {
  // Create a string with `c` number of `#` characters and pad it with spaces to reach length `n`
  return '#'.repeat(c).padEnd(n, ' ');
}

How It Works:

• We use the repeat() method to create a string with c # characters.
• We then use padEnd(n, ' ') to add spaces until the length of the string is n.

Comparison of Approaches

Approach	Pros	Cons
Initial Approach	Straightforward for beginners to understand.	More lines of code and manual space padding.
Optimized Approach	Simplifies code using built-in methods.	Requires familiarity with padEnd().

The optimized solution demonstrates how built-in JavaScript methods can reduce code complexity while improving readability.

Exploring Variations

To deepen your understanding, try modifying the exercise:

1. Inverted Steps: Create steps where the # characters start from the right.
2. Pyramid Shape: Center-align the steps to form a pyramid.
3. Diamond Shape: Combine two pyramids to form a diamond.

Key Takeaways

1. Loops: Mastering for loops is crucial for solving problems that require repeated actions.
2. String Manipulation: Built-in methods like repeat() and padEnd() can simplify tasks.
3. Modular Code: Splitting logic into separate functions (steps and print) makes the code more readable and easier to maintain.

Conclusion

This coding exercise is a great example of how simple tasks can be solved in multiple ways. Whether you’re new to JavaScript or a seasoned developer, practicing these types of challenges will sharpen your problem-solving skills. Give it a try, experiment with variations, and share your solutions!