Solutions to https://github.com/domenic/count-to-6

count-to-6-solutions.js

/***************** hello-es6.js *****************/


console.log('HELLO ES6');


/***************** template-strings.js *****************/


const name = process.argv[2];

const message = `Hello, ${name}!
Your name lowercased is "${name.toLowerCase()}".`;

console.log(message);


/***************** arrow-functions-1.js *****************/


const inputs = process.argv.slice(2);

// First, extract the first character of all input strings.
// Then, concatenate all those first chars with reduce.
const result = inputs.map(str => str.charAt(0))
    .reduce((chain, str) => {
        return `${chain}${str}`;
    }, '');

// No one will ever guess that format.
console.log(`[${inputs}] becomes "${result}"`);


/***************** arrow-functions-2.js *****************/


const foot = {
    kick() {
        this.yelp = 'Ouch!';

        setImmediate(() => {
            // Since we used an arrow function, `this` here is the same as `this` outside of the function.
            console.log(this.yelp);
        });
    },
};

foot.kick();


/***************** spread.js *****************/


const numbers = process.argv.splice(2, process.argv.length);

// Math.min can take lots of arguments.
const min = Math.min(...numbers);

// No one will ever guess that format.
console.log(`The minimum of [${numbers}] is ${min}`);


/***************** rest.js *****************/


module.exports = function average(...numbers) {
    // Using reduce to calculate a sum.
    const sum = numbers.reduce((last, num) => {
        return last + num;
    }, 0);

    return sum / numbers.length;
};


/***************** default-arguments-1.js *****************/


module.exports = function midpoint(x = 0, y = 1) {
    return (x + y) / 2;
};


/***************** default-arguments-2.js *****************/


module.exports = function(string, bangs = string.length) {
    // The repeat function is new in ES6.
    return string + '!'.repeat(bangs);
};


/***************** tagged-template.js *****************/


const inputName = process.argv[2];
const inputMessage = process.argv[3];

// The WTF exercise.
function html(str, name, message) {
    const escaped = message
        .replace(/&/g, '&')
        .replace(/'/g, ''')
        .replace(/"/g, '"')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;');

    return str[0] + name + str[1] + escaped + str[2];
}

// No one will ever guess that format.
console.log(html`<b>${inputName} says</b>: "${inputMessage}"`);