crystalattice

hardness_scale = {"talc": 1, "gypsum": 3, "calcite": 9}
minerals = {}

for a_key in hardness_scale.keys():
    minerals[a_key] = hardness_scale[a_key]
print(minerals) #{'talc': 1, 'gypsum': 3, 'calcite': 9}

for a_key in hardness_scale:
    minerals[a_key] = hardness_scale[a_key]
print(minerals) #{'talc': 1, 'gypsum': 3, 'calcite': 9}

crystalattice

d1 = {"a":1, "b":2, "c":3}
d2 = {"x":4, "y":5, "z":6}

for key in d1:
    d2[key] = d1[key]
    
# print(d2)
#{'x': 4, 'y': 5, 'z': 6, 'a': 1, 'b': 2, 'c': 3}

crystalattice

//Object creator

function createMyObject() {
  return {
    foo: "bar",
    answerToUniverse: 42,
    "olly olly": "oxen free",
    sayHello: function() {
      return "hello";
    }

crystalattice

What is scope? Your explanation should include the idea of global vs. local scope.

Scope is the namespace of a data element. Global scope encompasses the entire code project; global values can be called anywhere within the project. Local scope is contained with a particular function; other functions cannot access those values. It also means that functions within functions cannot be accessed outside the containing function.

Why are global variables avoided?

Global variables can overstep their bounds and cause unintended side effects if they are manipulated in a way that wasn't planned for. For example, if a developer has a global variable and a local variable with the same name, she may forget that fact and call the global variable instead of the local variable, changing the global value and ultimately changing the result of the program.

Explain JavaScript's strict mode

crystalattice

//Min-max
function max(numbers) {
  var high = numbers[0];
  for (var i = 0; i <= numbers.length; i++) {
    if (numbers[i] > high) {
      high = numbers[i];
    }
  }
  return high;
}

crystalattice

//Make List
function makeList(item1, item2, item3) {
  return list = [item1, item2, item3];
}

//Add to array
function addToList(list, item) {
  var list = list;
  list.push(item);
  return list;

crystalattice

//Traffic Light
function doTrafficLights() {
  var activeLight = getActiveLight();
  if (activeLight === "red"){
    turnRed();}
  else if (activeLight === "yellow"){
    turnYellow();}
  else if (activeLight === "green"){
    turnGreen();}

crystalattice

//Area
function computeArea(width, height) {
  return width * height;
}

//Temp conversion
function celsToFahr(celsTemp) {
  return (celsTemp * 9)/5 + 32;
}

crystalattice

//WisePerson generator
function wisePerson(wiseType, whatToSay) {
  return ("A wise " + wiseType + " once said: \"" +
      whatToSay + "\".");
  console.log(phrase);
}

//Shouter
function shouter(whatToShout) {
  return whatToShout.toUpperCase() + "!!!";

crystalattice

1) What is the 1994 rate of juvenile delinquency in the U.S.? Good
2) What can we do to reduce juvenile delinquency in the U.S.? Bad
  a) What has been done to address juvenile delinquency? 
  b) What are the most effective ways to reduce delinquency?
3) Does education play a role in reducing juvenile delinquents' return to crime? Good
4) How many customers does AT&T currently serve in Washington, DC? Good
5) What factors lead consumers to choose AT&T over other service providers? Good
6) How can AT&T attract more customers? Bad
  a) For a given scenario, does the number of customers increase?
7) Why did the Challenger Shuttle explode? Bad