D3 Examples - Sample problems 2: objects and arrays

xxxxxxxxxx
 
<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>
​
<body>
  <h1>Please look in the code below for 4 JavaScript practice problems.</h1>
  <p>(These problems don't include any SVG manipulation, so you will need to open the developer console in order to see the output of your code)</p>
  <script>
  // Problem 1: search array1 for those states whose location is "East"
  // using console.log(), print just the state name(s).
console.log("Question 1")
  array1 = [
                    {name: "Arizona",  location: "Southwest"},
            {name: "Virginia", location: "East"},
            {name: "Florida",  location: "Southeast"}
           ];
                array1.forEach(function (a){
            if (a.location == 'East')
              console.log(a.name)
          })
                    console.log("")
  // Problem 1 cont.: search array1 (above) for those states whose location contains the substring "South"
  // using console.log(), print just the state name(s) for these states.
            array1.forEach(function (a){
          if (a.location.includes('South'))
            console.log(a.name)
        })
        console.log("")
  // Problem 2: using iteration and console.log(), print those items that are in
  // array2 but NOT in array3
 console.log("Question 2")   
  array2 = ['a','b','c', 65, 'd'];
  array3 = ['a','c','e','f','g', 87];
    
    array2.forEach (function (x){
      if (array3.includes(x) ){
        return false
        
      }
        console.log (x)
    })
  
    
    
    
    
  console.log("")
  // Problem 3: 'states' is an array of objects. Sort the array in ascending order
  // by state name
  console.log("Question 3")
  states = [{name: "Alaska", id: "AK", population: 741894},
            {name: "Virginia", id: "VA", population: 8411808},
                    {name: "Arizona", id: "AZ", population: 6931071},
            {name: "Florida", id: "FL", population: 20984400}]
  states.sort(function (a,b) {
    if (a.name < b.name){
      return -1;
    } if (a.name > b.name){
      return 1;
    } 
  });   
  //Another Way to sort by their names.
    //states.sort(function(a,b){
            //return d3.ascending(a.name, b.name) })
    console.log(states)
  
            console.log("")
  // Problem 4: write code that determines which state(s) have a population value that is an even number. Print out the state(s) to the console
        console.log("Question 4")
            
     states.forEach(function (i){
      if ( i.population % 2 == 0){
        console.log(i)
      }
    })
  
  
​
  </script>
</body>
​
    