title: Populating an array using a for loop and another array
body: <p>This is more a learning exercise and nothing super critical - I'm unsure of the best way to Google what I'm looking for, I clicked through a few others suggested answers and didn't find anything that looked super relevant.  </p>
  
  <p>I'm wondering if there's a way I can populate an array using another array and a for loop (as opposed to modifying the contents of the existing array in place).  What I envision is something like:</p>
  
  <pre><code>var existingArray = ["Thing1", "Thing2", "Thing3"];
  
  let newArray = for (var i=0; i &lt; existingArray.length; i++) {
    "Modified string " + existingArray[i];
  }
  
  // Output: ["Modified string Thing1", "Modified string Thing2", "Modified string Thing3"]
  </code></pre>
  
  <p>where I can just create the new array variable and populate it more or less in the same block of code.  I know how to do it the maybe more traditional way where I just say:</p>
  
  <pre><code>newArray = [];
  oldArray = ["Thing1", "Thing2", "Thing3"]
  
  for (var i = 0; i &lt; oldArray.length; i++) {
    newArray.push("Modified string " + oldArray[i]);
  }
  </code></pre>
  
  <p>I'm sorry if this is a somewhat stupid question, I'm just curious if there's a way to do this and if there's any advantage to doing so.  It seems like it would be cool to just declare a new array and populate it all with one little chunk of code instead of declaring the new array, then using .push() to populate it.  </p>