Pyramid

Write a function that accepts a positive number N. The function should console log a pyramid shape with N levels using the # character.

Directions

Write a function that accepts a positive number N. The function should console log a pyramid shape with N levels using the # character. Make sure the pyramid has spaces on both the left *and* right hand sides

Examples#

pyramid(1)    '#'pyramid(2)    ' # '    '###'pyramid(3)    '  #  '    ' ### '    '#####'pyramid(1)
    '#'
pyramid(2)
    ' # '
    '###'
pyramid(3)
    '  #  '
    ' ### '
    '#####'

Try it first#

Copy the stub, make the 4 tests pass on your machine, then open the solution. The reveal is remembered per page in this browser.

JSexercises/pyramid/index.js

function pyramid(n) {} module.exports = pyramid;function pyramid(n) {}

module.exports = pyramid;

Solution#

JScompleted_exercises/pyramid/index.js

function pyramid(n, row = 0, level = '') {  if (row === n) {    return;  }   if (level.length === 2 * n - 1) {    console.log(level);    return pyramid(n, row + 1);  }   const midpoint = Math.floor((2 * n - 1) / 2);  let add;  if (midpoint - row <= level.length && midpoint + row >= level.length) {    add = '#';  } else {    add = ' ';  }  pyramid(n, row, level + add);} module.exports = pyramid;function pyramid(n, row = 0, level = '') {
  if (row === n) {
    return;
  }

  if (level.length === 2 * n - 1) {
    console.log(level);
    return pyramid(n, row + 1);
  }

  const midpoint = Math.floor((2 * n - 1) / 2);
  let add;
  if (midpoint - row <= level.length && midpoint + row >= level.length) {
    add = '#';
  } else {
    add = ' ';
  }
  pyramid(n, row, level + add);
}

module.exports = pyramid;
function pyramid(n) {  const midpoint = Math.floor((2 * n - 1) / 2);   for (let row = 0; row < n; row++) {    let level = '';     for (let column = 0; column < 2 * n - 1; column++) {      if (midpoint - row <= column && midpoint + row >= column) {        level += '#';      } else {        level += ' ';      }    }     console.log(level);  }}function pyramid(n) {
  const midpoint = Math.floor((2 * n - 1) / 2);

  for (let row = 0; row < n; row++) {
    let level = '';

    for (let column = 0; column < 2 * n - 1; column++) {
      if (midpoint - row <= column && midpoint + row >= column) {
        level += '#';
      } else {
        level += ' ';
      }
    }

    console.log(level);
  }
}
const pyramid = require('./index'); beforeEach(() => {  jest.spyOn(console, 'log');}); afterEach(() => {  console.log.mockRestore();}); test('pyramid is a function', () => {  expect(typeof pyramid).toEqual('function');}); test('prints a pryamid for n = 2', () => {  pyramid(2);  expect(console.log.mock.calls[0][0]).toEqual(' # ');  expect(console.log.mock.calls[1][0]).toEqual('###');  expect(console.log.mock.calls.length).toEqual(2);}); test('prints a pryamid for n = 3', () => {  pyramid(3);  expect(console.log.mock.calls[0][0]).toEqual('  #  ');  expect(console.log.mock.calls[1][0]).toEqual(' ### ');  expect(console.log.mock.calls[2][0]).toEqual('#####');  expect(console.log.mock.calls.length).toEqual(3);}); test('prints a pryamid for n = 4', () => {  pyramid(4);  expect(console.log.mock.calls[0][0]).toEqual('   #   ');  expect(console.log.mock.calls[1][0]).toEqual('  ###  ');  expect(console.log.mock.calls[2][0]).toEqual(' ##### ');  expect(console.log.mock.calls[3][0]).toEqual('#######');  expect(console.log.mock.calls.length).toEqual(4);}); const pyramid = require('./index');

beforeEach(() => {
  jest.spyOn(console, 'log');
});

afterEach(() => {
  console.log.mockRestore();
});

test('pyramid is a function', () => {
  expect(typeof pyramid).toEqual('function');
});

test('prints a pryamid for n = 2', () => {
  pyramid(2);
  expect(console.log.mock.calls[0][0]).toEqual(' # ');
  expect(console.log.mock.calls[1][0]).toEqual('###');
  expect(console.log.mock.calls.length).toEqual(2);
});

test('prints a pryamid for n = 3', () => {
  pyramid(3);
  expect(console.log.mock.calls[0][0]).toEqual('  #  ');
  expect(console.log.mock.calls[1][0]).toEqual(' ### ');
  expect(console.log.mock.calls[2][0]).toEqual('#####');
  expect(console.log.mock.calls.length).toEqual(3);
});

test('prints a pryamid for n = 4', () => {
  pyramid(4);
  expect(console.log.mock.calls[0][0]).toEqual('   #   ');
  expect(console.log.mock.calls[1][0]).toEqual('  ###  ');
  expect(console.log.mock.calls[2][0]).toEqual(' ##### ');
  expect(console.log.mock.calls[3][0]).toEqual('#######');
  expect(console.log.mock.calls.length).toEqual(4);
});

Verbatim from the repo at 30cf7634. Alternate tabs are the commented-out solutions with the leading // removed and nothing else changed. Run the tests locally with npx jest pyramid inside the fork.

Directions

Examples#

Try it first#

Solution#hide again

Solution#