Using JavaScript to Reverse an Array

We can use JavaScript to reverse an array by simply using the JavaScript Array reverse() method.

someArray.reverse();

Let’s see the reverse array in use with a simple example.

var numbersArray = [1,2,3,4,5,6,7,8,9,10];

//Reverse the order of the array
numbersArray.reverse();
console.log(numbersArray);

#Output:
[10, 9, 8, 7, 6, 5, 4, 3, 2, 1]

Notice that using the reverse method on an array will change the values of the array the method is called on.

Let’s take a look at an example using HTML.

Using JavaScript to Reverse an Array of Strings With a Click

In this example, we will have a large array of CSS color names that are supported by most browsers. We will set up some HTML to let the user see all the colors contained in the array. We will then have a button that will reverse the array of strings.

Here is the HTML set up:

<style>#colorDiv span { margin-right: 10px; display: inline-block; }</style>
<div id="colorDiv"></div>
<div id="div1">
  <div id="click-me" onclick="reverseColors()">Reverse colors</div>
  <div id="results"></div>
</div>

In the JavaScript portion of this example, we will first create the HTML span elements that will each contain their own color. We will do this by iterating over the cssColors array using a for loop. The cssColors array will contain 140+ String color names. We will add the colors to div “#colorDiv” using the appendChild() method.

We will then add an onclick event that will run the function to create the HTML, and then also reverse the array of colors using the reverse() method. We will then clear the HTML div containing our colors by changing the innerHTML to nothing, and remake it using the updated array.

Here is the JavaScript code:

var cssColors = ["AliceBlue","AntiqueWhite","Aqua","Aquamarine","Azure","Beige","Bisque","Black","BlanchedAlmond","Blue","BlueViolet","Brown","BurlyWood","CadetBlue","Chartreuse","Chocolate","Coral","CornflowerBlue","Cornsilk","Crimson","Cyan","DarkBlue","DarkCyan","DarkGoldenRod","DarkGray","DarkGrey","DarkGreen","DarkKhaki","DarkMagenta","DarkOliveGreen","DarkOrange","DarkOrchid","DarkRed","DarkSalmon","DarkSeaGreen","DarkSlateBlue","DarkSlateGray","DarkSlateGrey","DarkTurquoise","DarkViolet","DeepPink","DeepSkyBlue","DimGray","DimGrey","DodgerBlue","FireBrick","FloralWhite","ForestGreen","Fuchsia","Gainsboro","GhostWhite","Gold","GoldenRod","Gray","Grey","Green","GreenYellow","HoneyDew","HotPink","IndianRed","Indigo","Ivory","Khaki","Lavender","LavenderBlush","LawnGreen","LemonChiffon","LightBlue","LightCoral","LightCyan","LightGoldenRodYellow","LightGray","LightGrey","LightGreen","LightPink","LightSalmon","LightSeaGreen","LightSkyBlue","LightSlateGray","LightSlateGrey","LightSteelBlue","LightYellow","Lime","LimeGreen","Linen","Magenta","Maroon","MediumAquaMarine","MediumBlue","MediumOrchid","MediumPurple","MediumSeaGreen","MediumSlateBlue","MediumSpringGreen","MediumTurquoise","MediumVioletRed","MidnightBlue","MintCream","MistyRose","Moccasin","NavajoWhite","Navy","OldLace","Olive","OliveDrab","Orange","OrangeRed","Orchid","PaleGoldenRod","PaleGreen","PaleTurquoise","PaleVioletRed","PapayaWhip","PeachPuff","Peru","Pink","Plum","PowderBlue","Purple","RebeccaPurple","Red","RosyBrown","RoyalBlue","SaddleBrown","Salmon","SandyBrown","SeaGreen","SeaShell","Sienna","Silver","SkyBlue","SlateBlue","SlateGray","SlateGrey","Snow","SpringGreen","SteelBlue","Tan","Teal","Thistle","Tomato","Turquoise","Violet","Wheat","White","WhiteSmoke","Yellow","YellowGreen"];

//Populate HTML with colors in cssColors array
for (var i = 0; i < cssColors.length; i++) {
  var newColor = document.createElement('span');
  newColor.textContent = cssColors[i];
  document.getElementById("colorDiv").appendChild(newColor);
}

function reverseColors() {
  
  //Reverse colors
  cssColors.reverse();
  
  //Clear HTML of old colors
  document.getElementById("colorDiv").innerHTML = "";
  
  //Populate HTML with colors in cssColors array after reversing colors
  for (var i = 0; i < cssColors.length; i++) {
    var newColor = document.createElement('span');
    newColor.textContent = cssColors[i];
    document.getElementById("colorDiv").appendChild(newColor);
  }
  
};

The final code and output for this example is below:

Code Output:

Full Code:

<style>#colorDiv span { margin-right: 10px; display: inline-block; }</style>
<div id="colorDiv"></div>
<div id="div1">
  <div id="click-me" onclick="reverseColors()">Reverse colors</div>
  <div id="results"></div>
</div>

<script>

var cssColors = ["AliceBlue","AntiqueWhite","Aqua","Aquamarine","Azure","Beige","Bisque","Black","BlanchedAlmond","Blue","BlueViolet","Brown","BurlyWood","CadetBlue","Chartreuse","Chocolate","Coral","CornflowerBlue","Cornsilk","Crimson","Cyan","DarkBlue","DarkCyan","DarkGoldenRod","DarkGray","DarkGrey","DarkGreen","DarkKhaki","DarkMagenta","DarkOliveGreen","DarkOrange","DarkOrchid","DarkRed","DarkSalmon","DarkSeaGreen","DarkSlateBlue","DarkSlateGray","DarkSlateGrey","DarkTurquoise","DarkViolet","DeepPink","DeepSkyBlue","DimGray","DimGrey","DodgerBlue","FireBrick","FloralWhite","ForestGreen","Fuchsia","Gainsboro","GhostWhite","Gold","GoldenRod","Gray","Grey","Green","GreenYellow","HoneyDew","HotPink","IndianRed","Indigo","Ivory","Khaki","Lavender","LavenderBlush","LawnGreen","LemonChiffon","LightBlue","LightCoral","LightCyan","LightGoldenRodYellow","LightGray","LightGrey","LightGreen","LightPink","LightSalmon","LightSeaGreen","LightSkyBlue","LightSlateGray","LightSlateGrey","LightSteelBlue","LightYellow","Lime","LimeGreen","Linen","Magenta","Maroon","MediumAquaMarine","MediumBlue","MediumOrchid","MediumPurple","MediumSeaGreen","MediumSlateBlue","MediumSpringGreen","MediumTurquoise","MediumVioletRed","MidnightBlue","MintCream","MistyRose","Moccasin","NavajoWhite","Navy","OldLace","Olive","OliveDrab","Orange","OrangeRed","Orchid","PaleGoldenRod","PaleGreen","PaleTurquoise","PaleVioletRed","PapayaWhip","PeachPuff","Peru","Pink","Plum","PowderBlue","Purple","RebeccaPurple","Red","RosyBrown","RoyalBlue","SaddleBrown","Salmon","SandyBrown","SeaGreen","SeaShell","Sienna","Silver","SkyBlue","SlateBlue","SlateGray","SlateGrey","Snow","SpringGreen","SteelBlue","Tan","Teal","Thistle","Tomato","Turquoise","Violet","Wheat","White","WhiteSmoke","Yellow","YellowGreen"];

for (var i = 0; i < cssColors.length; i++) {
  var newColor = document.createElement('span');
  newColor.textContent = cssColors[i];
  document.getElementById("colorDiv").appendChild(newColor);
}

function reverseColors() {
  cssColors.reverse();
  document.getElementById("colorDiv").innerHTML = "";
  for (var i = 0; i < cssColors.length; i++) {
    var newColor = document.createElement('span');
    newColor.textContent = cssColors[i];
    document.getElementById("colorDiv").appendChild(newColor);
  }
};

</script>

Hopefully this article has been helpful for you to learn how to use JavaScript to reverse an array.