Check Writing + forEach re @TheIronYard--Orlando Coding Dojos

check-writing.js

var assert = require('assert');

function test(actual, expected, success){
    success = success || 'pass!';

    assert(actual === expected) || console.log(success);
}

/**
 * Check Writing
 *
 * Given an Number representing money -- $1234.56 -- convert
 * that into it's string representation in English words. For
 * example, 1234.56 is "one thousand, two hundred thirty four
 * and 56/100s", just like you would see on a check.
 *
 * In a lot of ways, this is the inverse of the "String Calculator"
 * problem, so a lot of what you've learned there will be put into
 * practice here, but backwards. Hooray!
 */

/**
 * Sample Data:
 *
 * $ 1234.56 => "one thousand, two hundred thirty four and 56/100s"
 * $ 123.45  => "one hundred twenty three and 45/100s"
 * $ 12.34   => "twleve and 34/100s"
 * $ 1.23    => "one and 23/100s"
 *
 * EXTRA CREDIT!
 *
 * $ 12,345,678.90 =>
 * "twelve million, three hundred fourty five thousand, six hundred
 *   seventy eight and 90/100s"
 *
 * Make up your own, too.
 */

function toEnglish(value){
    var ones = [ 'zero', 'one', 'two', 'three', /* . . . */ ];

    var tens = [ 'ten', 'twenty', 'thirty', 'forty', /* . . . */ ];

    // 123.45 >> 'one hundred twenty three and 45/100s'

    // 123.45 >> ensure 2 decimal places AND convert to String >> 123.45
    // 123    >> ensure 2 decimal places AND convert to String >> 123.00
    value = Number(value).toFixed(2);

    //      '123.45'
    //      '123.00'
    //     '1234.56'
    //    '12345.67'
    //        '1.00'
    //       '42.00'
    //     '7247.86'
    // Using String.slice()...

    var cents = value.slice(-2);

    var dollars = value.slice(0, -3);

    var english = cents + '/100s dollars';

    /* Then a miracle happens */
    { /* . . . */ }

    return english;
}


var testCases = [
    [0, 'zero' ],
    [1, 'one' ],
    [2, 'two' ],
    [3, 'three' ],
    [123, 'one hundred twenty three' ]
];

{ // BLOCK OF CONVENIENCE
    var actual, expected;

    for ( var index = 0; index < testCases.length; index++ ){
        actual = toEnglish(testCases[index][0]);

        expected = testCases[index][1];

        assert.strictEqual(actual, expected);
    }

    actual; // {toEnglish(123)}
    expected; // {'one hundred twenty three'}
} // END BLOCK OF CONVENIENCE

testCases.forEach(function(testCase){
    var actual = toEnglish(testCase[0]),
        expected = testCase[1];

    assert.strictEqual(toEnglish(testCase[0]), testCase[1],
        testCase[0] + ' >> ' + testCase[1]);
});

// Assuming the `for` loop above did not exist...
actual; // {undefined}
expected; // {undefined}

test(1, 'one and 00/100s dollars');
test(2, 'two and 00/100s dollars');
test(3, 'three and 00/100s dollars');
test(4, 'four and 00/100s dollars');
test(5, 'five and 00/100s dollars');
test(1.23, 'one and 23/100s dollars');
test(12.34, 'twelve and 34/100s dollars');
test(123.45, 'one hundred twenty three and 45/100s dollars');