reduceRight()

In Google Apps Script, the reduceRight() method is an array method that works the same way as the reduce() method, but it iterates over the elements in the array from right to left instead of from left to right. The method takes a callback function as an argument, which is called for each element in the array from right to left. The callback function should return the accumulated result of the previous iterations and the current value of the element.

Here is an example of using the reduceRight() method to concatenate the elements in an array:

var array = ["a", "b", "c", "d"];

// Concatenate the elements in the array from right to left
var result = array.reduceRight(function(acc, curr) {
  return acc + curr;
});

// Output the concatenated string
Logger.log(result); // Outputs: "dcba"

In this example, we call the reduceRight() method on the array and pass a callback function that concatenates each element from right to left. The method iterates over each element in the array from right to left and calls the callback function for each element, passing the accumulated result of the previous iterations and the current value of the element as arguments. The callback function concatenates the accumulated result and the current value of the element, and returns the concatenated string as the new accumulated result. The reduceRight() method returns the final accumulated result, which is a concatenated string of all the elements in the array from right to left, and is assigned to a variable called result, and is outputted to the log using the Logger.log() method.

You can also use the reduceRight() method to find the longest string in an array:

var array = ["dog", "cat", "elephant", "lion", "giraffe"];

// Find the longest string in the array
var longest = array.reduceRight(function(acc, curr) {
  return acc.length > curr.length ? acc : curr;
});

// Output the longest string
Logger.log(longest); // Outputs: "elephant"

In this example, we call the reduceRight() method on the array and pass a callback function that finds the longest string. The method iterates over each element in the array from right to left and calls the callback function for each element, passing the accumulated result of the previous iterations and the current value of the element as arguments. The callback function checks whether the length of the accumulated result is greater than the length of the current value of the element, and returns either the accumulated result or the current value of the element as the new accumulated result. The reduceRight() method returns the final accumulated result, which is the longest string in the array, and is assigned to a variable called longest, and is outputted to the log using the Logger.log() method.