Custom method case in javascript

JavaScript is a widely used programming language that allows developers to implement custom methods by writing functions. In this article, we will share some examples of custom methods in JavaScript that can achieve different functions.

1. Average of array

Arrays in JavaScript have many commonly used methods, such as push (adding elements), pop (removing elements), etc. However, custom methods allow us to implement more complex logic.

For example, we can calculate the average of all numbers in an array through a custom method:

function averageArray(arr) {
  var sum = 0;
  for(var i = 0; i < arr.length; i++) {
    sum += arr[i];
  }
  return sum / arr.length;
}

In this example, we define a method called "averageArray" that accepts Takes an array as argument and returns the average of all numbers in this array. This method uses a for loop to calculate the sum by looping through each number in the array and adding them, and finally divides the sum by the length of the array to find the average.

2. Flipping Strings

Another common JavaScript customization method is to flip strings, such as converting "hello" to "olleh".

The following is a custom method to implement flipping a string:

function reverseString(str) {
  var splitString = str.split(""); 
  var reverseArray = splitString.reverse(); 
  var joinArray = reverseArray.join(""); 
  return joinArray; 
}

In this example, we define a method named "reverseString" that accepts a string as a parameter and Returns a flipped string. This method uses the split (split the string into an array), reverse (reverse the order of the array elements), and join (combine the array elements into a string) methods in order to flip the string.

3. Find the maximum and minimum values ​​in an array

Custom methods can also be used to find the maximum and minimum values ​​in an array. Here is a JavaScript custom method that implements this functionality:

function getMax(arr) {
  var max = arr[0];
  for(var i = 1; i < arr.length; i++) {
    if(arr[i] > max) {
      max = arr[i];
    }
  }
  return max;
}

function getMin(arr) {
  var min = arr[0];
  for(var i = 1; i < arr.length; i++) {
    if(arr[i] < min) {
      min = arr[i];
    }
  }
  return min;
}

In this example, we define two custom methods, "getMax" and "getMin", both of which accept an array as parameters and returns the maximum and minimum values ​​in the array. The method uses a for loop to iterate through each element in the array to find the maximum and minimum values ​​and return them.

Summary

Custom methods in JavaScript allow us to implement more complex logic and make our code more readable. In this article, we shared some examples of custom methods in JavaScript, such as calculating the average of an array, flipping a string, and finding the maximum and minimum values ​​in an array. Through these examples, developers can better understand how to create custom methods and apply them to their own code.

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