AmitDiwan has Published 10744 Articles

Remove '0','undefined' and empty values from an array in JavaScript

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:21:15

240 Views

To remove ‘0’. ‘undefined’ and empty values, you need to use the concept of splice(). Let’s say the following is our array −var allValues = [10, false, 100, 150 ,'', undefined, 450, null]Following is the complete code using for loop and splice() −Examplevar allValues = [10, false, 100, 150 ,'', ... Read More

Display all the numbers from a range of start and end value in JavaScript?

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:14:55

890 Views

Let’s say the following is our start value −var startValue=10;Let’s say the following is our end value −var endValue=20;Use the for loop to fetch numbers between the start and end value −Examplevar startValue=10; var endValue=20; var total=''; function printAllValues(startValue, endValue){    for(var start=startValue;start < endValue ;start++){       total=total+start+", ... Read More

How could I write a for loop that adds up all the numbers in the array to a variable in JavaScript?

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:14:02

942 Views

At first, declare and initialize the total variable with 0 and then you need to iterate over all the array and extract all the values of array and add up with the updated total variable.Let’s say the following is our array with numbers −var listOfValues = [10, 3, 4, 90, ... Read More

Capitalize only the first letter after colon with regex and JavaScript?

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:13:12

1K+ Views

To capitalize only the first letter, use the concept of regular expression along with toUpperCase(). Since the toUpperCase() capitalize the entire string, we need to use Regex to only capitalize the first letter after colon.Let’s say the following is our string −var objectValues='fullName: john Smith';Here’s the complete code to capitalize ... Read More

Any way to solve this without concatenating these two arrays to get objects with higher value?

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:12:08

53 Views

To get objects with specific property, use the concept of reduce() on both arrays individually. You don’t need to concatenate. Let’s say the following are our objects with student name and student marksvar sectionAStudentDetails = [    {studentName: 'John', studentMarks: 78},    {studentName: 'David', studentMarks: 65},    {studentName: 'Bob', studentMarks: ... Read More

Filter array of objects by a specific property in JavaScript?

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:10:43

563 Views

Use the concept of map() along with ternary operator (?). Following are our array of objects −let firstCustomerDetails = [    {firstName: 'John', amount: 100},    {firstName: 'David', amount: 50},    {firstName: 'Bob', amount: 80} ];    let secondCustomerDetails = [    {firstName: 'John', amount: 400},    {firstName: 'David', amount: ... Read More

JavaScript creating an array from JSON data?

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:09:27

921 Views

To create an array from JSON data, use the concept of map() from JavaScript. Let’s say the following is our data −const studentDetails =[    {       name : "John"    },    {       name : "David"    },    {       name ... Read More

Is there a “null coalescing” operator in JavaScript?

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:08:05

198 Views

Yes, JavaScript now supports the “null coalescing” operator, but you can also use the concept of logical OR (||). The syntax is as follows −var anyVariableName=null; var anyVariableName=yourVariableName || yourActualValue;Examplevar fullName=null; console.log("The full name is="+fullName); var actualName=fullName || "David Miller"; console.log("The full name is="+actualName);To run the above program, you need ... Read More

Accessing variables in a constructor function using a prototype method with JavaScript?

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:05:35

921 Views

For this, use a “prototype”. JavaScript objects inherit properties and methods from a prototype. For accessing variables, we have also used the “this” in JavaScript.Examplefunction Customer(fullName){    this.fullName=fullName; } Customer.prototype.setFullName = function(newFullName){    this.fullName=newFullName; } var customer=new Customer("John Smith"); console.log("Using Simple Method = "+ customer.fullName); customer.setFullName("David Miller"); console.log("Using Prototype Method ... Read More

How to remove li elements on button click in JavaScript?

AmitDiwan

AmitDiwan

Updated on 07-Sep-2020 08:04:37

4K+ Views

Let’s say the following is our Unordered List (ul) −    JavaScript Remove        MySQL Remove        MongoDB Remove        Java Remove Above, you can see the “Remove” button with every li element. On clicking this button, you can remove any li element.Following is ... Read More

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