w2d2_checkpoint_dustin.js

//1. Write a function average that takes two numbers as input (parameters), and returns the average of those numbers.
function average(num1, num2) { // Good Job!
	return (num1 + num2) / 2;
}

//2. Write a function greeter that takes a name as an argument and greets that name by returning something along the lines of "Hello, <name>!"
function greeting(name) { // Good Job!
	console.log('Hello ' + name + '!');
}

//3. Write the following functions that each accept a single number as an argument:

//even: returns true if its argument is even, and false otherwise.
function isEven(num) { // Good Job!
	if (num % 2 === 0) {
		return true;
	}
	return false;
}

//odd: the opposite of the above.
function isOdd(num) { // Good Job!
	if (num %2 !== 0) {
		return true;
	}
	return false;
}

//positive: returns true if its argument is positive, and false otherwise.
function isPossitive(num) { // Good Job!
	if (num >= 0) {
		return true;
	}
	return false;
}

//negative: the opposite of the above.
function isNegative(num) { // Good Job!

	if (num < 0) {
		return true;
	}
	return false;

}

//4. Write a function sayHello that takes a language parameter, and returns "hello" in that language. Make the function work with at least three languages.
function language(para) { // Good Job!

	if (para === 'english') {
		return 'Hello';
	} else if (para === 'french') {
		return 'Bonjour';
	} else if (para === 'spanish') {
		return 'Hola';
	}
}

//5. Write a function validCredentials that accepts two parameters: username and password, and returns true if both are long enough, and false otherwise. You can decide what constitutes "long enough".
function validCredentials(username, password) { // Good Job!
	if (username.length >= 6 && password >= 10) {
		return true;
	}

	return false;
}

//6. Repeating a String n Times: Let's write a function called repeatString that takes two parameters: a string str, which is the string to be repeated, and count -- a number representing how many times the string str should be repeated, e.g.

function repeatString(str, count) { // Good Job!
	var newStr = '';

	for (var i = 0; i < count; i++) {
		newStr += str;
	}

	return newStr;
}
repeatString('dog', 0); // => ''
repeatString('dog', 1); // => 'dog'
repeatString('dog', 2); // => 'dog' + 'dog' => 'dogdog'
repeatString('dog', 3); // => 'dog' + 'dog' + 'dog' => 'dogdogdog'


//7. Write a function called average that takes an array of numbers as a parameter and returns the average of those numbers.
function ave(array) { // Good Job!

	var average = 0;
	var sum = 0;
	for (var i = 0; i < array.length; i++) {
		sum += array[i];
	}
	average = sum / (array.length);

	return average;
}


//8. Write a function countWords that, when given a string as an argument, returns an object where keys are the words in the string, and values are the number of occurrences of that word within the string:

function countWords(s) { // Good Job!
	var words = s.split(' ');
	var result = {};
	var count = 0;
	for (var i = 0; i < words.length; i++) {
		var prop = words[i];
		if (prop in result) {
			count += 1;
			result[prop] = count;
		} else {
			result[prop] = count;
			count +=1
		}
	}
	return result;
}
countWords("hello hello"); // => {"hello": 2}
countWords("Hello hello"); // => {"Hello": 1, "hello": 1}
countWords("The quick brown"); // => {"The": 1, "quick": 1, "brown": 1}
HINT: You will want to make use of the string method split. Try \"Hello hello".split(" ") at a console to see how it works.

// Modify countWords to be case insensitive by using the following string method (experiment at a console with it to learn its behavior):
// "HElLo".toLowerCase(); // => ???

function countWords(s) { // Good Job!
	var words = s.toLowerCase().split(' ');
	var result = {};
	var count = 0;
	for (var i = 0; i < words.length; i++) {
		var prop = words[i];
		if (prop in result) {
			count += 1;
			result[prop] = count;
		} else {
			result[prop] = count;
			count +=1
		}
	}
	return result;
}
// Read about the join method on MDN and use it to implement a function that accepts a string as an argument and returns that string reversed.
function reverse(str) { // Good Job!
	var temp = str.split(' ');
	var reverseStr = [];
	for (var i = str.length - 1; i >= 0; i--) {
		reverseStr.push(str[i]);
	}
	return reverseStr.join(' ');
}

// The function Object.keys returns an array of an object's keys. Experiment with it at the console like this:

// Object.keys({a: 1, b: 2});