Basic JavaScript 090

61-Comparison with the Less Than Or Equal To Operator

function testLessOrEqual(val) {
  if (val <= 12) {  // Change this line
    return "Smaller Than or Equal to 12";
  }

  if (val <= 24) {  // Change this line
    return "Smaller Than or Equal to 24";
  }

  return "25 or More";
}

// Change this value to test
testLessOrEqual(10);

62-Comparisons with the Logical And Operator

function testLogicalAnd(val) {
  // Only change code below this line

  if ( val<=50 && val>= 25 ) {
    return "Yes";
  }

  // Only change code above this line
  return "No";
}

// Change this value to test
testLogicalAnd(10);

63-Comparisons with the Logical Or Operator

function testLogicalOr(val) {
  // Only change code below this line

  if (val<10 || val>20) {
    return "Outside";
  }

  // Only change code above this line
  return "Inside";
}

// Change this value to test
testLogicalOr(15);

64-Introducing Else Statements

function testElse(val) {
  var result = "";
  // Only change code below this line

  if (val > 5) {
    result = "Bigger than 5";
  } else {
    result = "5 or Smaller";
  }

  // Only change code above this line
  return result;
}

// Change this value to test
testElse(4);

65-Introducing Else If Statements

function testElseIf(val) {
  if (val > 10) {
    return "Greater than 10";
  } 

  else if(val < 5) {
    return "Smaller than 5";
  } 

  else{
    return "Between 5 and 10";  
  }

}

// Change this value to test
testElseIf(7);

66-Logical Order in If Else Statements

function orderMyLogic(val) {
  if (val < 5) {
    return "Less than 5";
  } else if (val < 10) {
    return "Less than 10";
  } else {
    return "Greater than or equal to 10";
  }
}

// Change this value to test
orderMyLogic(7);

67-Chaining If Else Statements

function testSize(num) {
  // Only change code below this line

  var result = "";

  if (num>=20){
    result = "Huge";
  }

  else if (num<5){
    result = "Tiny";
  }   

  else if (num<10){
    result = "Small";
  }  

  else if (num<15){
    result = "Medium";
  }

  else if (num<20){
    result = "Large";
  }

  return result;
  // Only change code above this line
}

// Change this value to test
testSize(19);

68-Golf Code

function golfScore(par, strokes) {
  // Only change code below this line

  var result = "";

  if (strokes==1){
    result = "Hole-in-one!";
  }

  else if (strokes<=par-2){
    result = "Eagle";
  }

  else if (strokes==par-1){
    result = "Birdie";
  }

  else if (strokes===par){
    result = "Par";
  }

  else if (strokes==par+1){
    result = "Bogey";
  }

  else if (strokes==par+2){
    result = "Double Bogey";
  }

  else if (strokes>=par+3){
    result = "Go Home!";
  }


  return result;
  // Only change code above this line
}

// Change these values to test
golfScore(5, 4);

69-Selecting from many options with Switch Statements

function caseInSwitch(val) {
  var answer = "";
  // Only change code below this line

  switch (val){
    case 1:
      answer = "alpha";
      break;

    case 2:
      answer = "beta";
      break;

    case 3:
      answer = "gamma";
      break;

    case 4:
      answer = "delta";
      break;

  }


  // Only change code above this line  
  return answer;  
}

// Change this value to test
caseInSwitch(1);

70-Adding a default option in Switch statements

function switchOfStuff(val) {
  var answer = "";
  // Only change code below this line

  switch(val){
    case "a":
      answer = "apple";
      break;

    case "b":
      answer = "bird";
      break;

    case "c":
      answer = "cat";
      break;

    default:
      answer = "stuff";
  }

  // Only change code above this line  
  return answer;  
}

// Change this value to test
switchOfStuff("a");

71-Multiple Identical Options in Switch Statements

function sequentialSizes(val) {
  var answer = "";
  // Only change code below this line

  switch(val){
    case 1:
    case 2:
    case 3:
      answer = "Low";
      break;

    case 4:
    case 5:
    case 6:
      answer = "Mid";
      break;

    case 7:
    case 8:
    case 9:
      answer = "High";
      break;
  }

  // Only change code above this line  
  return answer;  
}

// Change this value to test
sequentialSizes(1);

72-Replacing If Else Chains with Switch

function chainToSwitch(val) {
  var answer = "";
  // Only change code below this line

  switch(val){
    case "bob":
      answer = "Marley";
      break;

    case 42:
      answer = "The Answer";
      break;

    case 1:
      answer = "There is no #1";
      break;

    case 99:
      answer = "Missed me by this much!";
      break;

    case 7:
      answer = "Ate Nine";
      break;
  }

  // Only change code above this line  
  return answer;  
}

// Change this value to test
chainToSwitch(7);

73-Returning Boolean Values from Functions

function isLess(a, b) {
  // Fix this code
  return a < b;
}

// Change these values to test
isLess(10, 15);

74-Return Early Pattern for Functions

// Setup
function abTest(a, b) {
  // Only change code below this line

  if (a<0 || b<0){
    return undefined;
  }

  // Only change code above this line

  return Math.round(Math.pow(Math.sqrt(a) + Math.sqrt(b), 2));
}

// Change values below to test your code
abTest(2,2);

75-Counting Cards

var count = 0;

function cc(card) {
  // Only change code below this line

  switch(card){
    case 2:
    case 3:
    case 4:
    case 5:
    case 6:
      count = count + 1;
      break;
    case 7:
    case 8:
    case 9:
      break;
    case 10:
    case "J":
    case "Q":
    case "K":
    case "A":
      count = count -1;
      break;
  }

  if(count===0){
    return "0 Hold";
  } 
  else if(count>0){
    return count + " Bet";
  }
  else if(count<0){
    return count + " Hold";
  }

  // Only change code above this line
}

// Add/remove calls to test your function.
// Note: Only the last will display
cc(2); cc(3); cc(7); cc('K'); cc('A');

76-Build JavaScript Objects

// Example
var ourDog = {
  "name": "Camper",
  "legs": 4,
  "tails": 1,
  "friends": ["everything!"]
};

// Only change code below this line.

var myDog = {
  "name": "snoopy",
  "legs": 2,
  "tails": 1,
  "friends": ["lala", "xixi"]
};

77-Accessing Objects Properties with the Dot Operator

// Setup
var testObj = {
  "hat": "ballcap",
  "shirt": "jersey",
  "shoes": "cleats"
};

// Only change code below this line

var hatValue = testObj.hat;      // Change this line
var shirtValue = testObj.shirt;    // Change this line

78-Accessing Objects Properties with Bracket Notation

// Setup
var testObj = {
  "an entree": "hamburger",
  "my side": "veggies",
  "the drink": "water"
};

// Only change code below this line

var entreeValue = testObj["an entree"];   // Change this line
var drinkValue = testObj["the drink"];    // Change this line

79-Accessing Objects Properties with Variables

// Setup
var testObj = {
  12: "Namath",
  16: "Montana",
  19: "Unitas"
};

// Only change code below this line;

var playerNumber = 16;       // Change this Line
var player = testObj[playerNumber];   // Change this Line

80-Updating Object Properties

// Example
var ourDog = {
  "name": "Camper",
  "legs": 4,
  "tails": 1,
  "friends": ["everything!"]
};

ourDog.name = "Happy Camper";

// Setup
var myDog = {
  "name": "Coder",
  "legs": 4,
  "tails": 1,
  "friends": ["Free Code Camp Campers"]
};

myDog.name = "Happy Coder";

// Only change code below this line.

81-Add New Properties to a JavaScript Object

// Example
var ourDog = {
  "name": "Camper",
  "legs": 4,
  "tails": 1,
  "friends": ["everything!"]
};

ourDog.bark = "bow-wow";

// Setup
var myDog = {
  "name": "Happy Coder",
  "legs": 4,
  "tails": 1,
  "friends": ["Free Code Camp Campers"]
};

myDog.bark = "woof";

// Only change code below this line.

82-Delete Properties from a JavaScript Object

// Example
var ourDog = {
  "name": "Camper",
  "legs": 4,
  "tails": 1,
  "friends": ["everything!"],
  "bark": "bow-wow"
};

delete ourDog.bark;

// Setup
var myDog = {
  "name": "Happy Coder",
  "legs": 4,
  "tails": 1,
  "friends": ["Free Code Camp Campers"],
  "bark": "woof"
};

delete myDog.tails;

// Only change code below this line.

83-Using Objects for Lookups

// Setup
function phoneticLookup(val) {
  var result = "";

  // Only change code below this line

  var lookup = {
    alpha:"Adams",
    bravo: "Boston",
    charlie: "Chicago",
    delta: "Denver",
    echo: "Easy",
    foxtrot: "Frank"
  };

  result = lookup[val];


  // Only change code above this line
  return result;
}

// Change this value to test
phoneticLookup("charlie");

84-Testing Objects for Properties

• 不能用 dot 要用 bra陣列陣列一樣嘛ket notation，有人說是因為資料存在變數裡面(就像是)

• https://forum.freecodecamp.org/t/freecodecamp-challenge-guide-testing-objects-for-properties/18324/4

// 初始化变量
var myObj = {
  gift: "pony",
  pet: "kitten",
  bed: "sleigh"
};

function checkObj(checkProp) {
  // 请把你的代码写在这条注释以下


  IfInthere = myObj.hasOwnProperty(checkProp);
  result = "";

  if(IfInthere){
    result = myObj[checkProp];
    return result;
  } 
  else {
    result = "Not Found";
    return result;
  }

}

// 你可以修改这一行来测试你的代码
checkObj("gift");


---

85-Manipulating Complex Objects

```js

var myMusic = [
  {
    "artist": "Billy Joel",
    "title": "Piano Man",
    "release_year": 1973,
    "formats": [ 
      "CS", 
      "8T", 
      "LP" ],
    "gold": true
  },
  // Add record here
  {
    "artist": "Chiu",
    "title": "SMS life",
    "release_year": 2017,
    "formats": ["sad", "angry", "helpless"]
  }
];

86-Accessing Nested Objects

- 有空格的屬性，用

// Setup
var myStorage = {
  "car": {
    "inside": {
      "glove box": "maps",
      "passenger seat": "crumbs"
     },
    "outside": {
      "trunk": "jack"
    }
  }
};

// Only change code below this line

var gloveBoxContents = myStorage.car.inside["glove box"]; // Change this line

87-Accessing Nested Arrays

• 物件的屬性存取可以用 dot 或是 bracket notation

• 陣列的內容存取只能用 []

// Setup
var myPlants = [
  { 
    type: "flowers",
    list: [
      "rose",
      "tulip",
      "dandelion"
    ]
  },
  {
    type: "trees",
    list: [
      "fir",
      "pine",
      "birch"
    ]
  }  
];

// Only change code below this line

var secondTree = myPlants[1].list[1]; // Change this line

88-Iterate with JavaScript For Loops

• for ([initialization]; [condition]; [final-expression])

// Example
var ourArray = [];

for (var i = 0; i < 5; i++) {
  ourArray.push(i);
}

// Setup
var myArray = [];

for (var i = 1; i < 6; i++){
  myArray.push(i);
}

// Only change code below this line.

89-Iterate Odd Numbers With a For Loop

// Example
var ourArray = [];

for (var i = 0; i < 10; i += 2) {
  ourArray.push(i);
}

// Setup
var myArray = [];

for (var i = 1; i < 10; i += 2){
  myArray.push(i);
}

// Only change code below this line.

90-Count Backwards With a For Loop

// Example
var ourArray = [];

for (var i = 10; i > 0; i -= 2) {
  ourArray.push(i);
}

// Setup
var myArray = [];

// Only change code below this line.

for (var i=9; i>0; i-=2){
  myArray.push(i);
}