JavaScript Array reduceRight() Method
Below is the example of Array reduceRight() method.
- Example:
HTML
<!DOCTYPE html><html> <head> <title> JavaScript Array reduceRight() Method </title></head> <body style="text-align:center;"> <h1 style="color: green;">GeeksforGeeks</h1> <p> Click here to get the Subtract of array elements from the left side </p> <button onclick="myGeeks()"> Click Here! </button> <br><br> Subtract: <span id="GFG"></span> <!-- Script to use reduceRight method --> <script> var arr = [175, 50, 25]; function subofArray(total, num) { return total - num; } function myGeeks(item) { document.getElementById("GFG").innerHTML = arr.reduceRight(subofArray); } </script></body> </html> |
Output:
The arr.reduceRight() method in JavaScript is used to convert elements of the given array from right to left to a single value.
Syntax:
array.reduceRight( function(total, currentValue, currentIndex, arr), initialValue )
Parameter: This method accepts five parameters as mentioned above and described below:
- function(total, currentValue, index, arr): It is the required parameter and used to run for each element of array. It contains four parameter which are listed below:
- total: It is required parameter and used to specify the initialValue, or the previously returned value of the function.
- currentValue: It is required parameter and used to specify the value of the current element.
- currentIndex: It is optional parameter and used to specify the array index of the current element.
- arr: It is optional parameter and used to specify the array object the current element belongs to.
- initialValue: It is optional parameter and used to specify the value to be passed to the function as the initial value.
Example 1: This example use reduceRight() method to return the subtract of all array elements from right.
HTML
<!DOCTYPE html><html> <head> <title> JavaScript Array reduceRight() Method </title></head> <body style="text-align:center;"> <h1 style="color: green;">GeeksforGeeks</h1> <p> Click here to get the Subtract of array elements from right </p> <button onclick="myGeeks()"> Click Here! </button> <br><br> Subtract: <span id="GFG"></span> <!-- Script to use reduceRight method --> <script> var arr = [10, 20, 30, 40, 50, 60]; function subofArray(total, num) { return total - num; } function myGeeks(item) { document.getElementById("GFG").innerHTML = arr.reduceRight(subofArray); } </script></body> </html> |
Output:
Example 2: This example use reduceRight() method to return the round sum of all array elements. The code performing sum that does not affect by the reduceRight() method.
HTML
<!DOCTYPE html><html> <head> <title> JavaScript Array reduceRight() Method </title></head> <body style="text-align:center;"> <h1 style="color: green;">GeeksforGeeks</h1> <p> Click here to get the sum of array elements </p> <button onclick="myGeeks()"> Click Here! </button> <br><br> Sum: <span id="GFG"></span> <!-- Script to use reduceRight method --> <script> var arr = [1.5, 20.3, 11.1, 40.7]; function sumofArray(sum, num) { return sum + Math.round(num); } function myGeeks(item) { document.getElementById("GFG").innerHTML = arr.reduceRight(sumofArray, 0); } </script></body> </html> |
Output:
Supported Browsers: The browsers supported by JavaScript Array reduceRight() method are listed below:
- Google Chrome 3
- Microsoft Edge 12
- Mozilla Firefox 3.0
- Safari 5
- Opera 10.5
- Internet Explorer 9
.png)