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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to remove the hash from window.location (URL) with JavaScript without page refresh?
The replaceState() method replaces the current history entry with the state objects, title, and URL passed as method parameters. This method is useful when you want to update the current history entry's state object or URL in response to a user action. To remove the hash from a URL without triggering a page refresh, we can use the HTML5 History API's replaceState() method. This approach modifies the browser's address bar while keeping the user on the same page. Syntax The syntax for the replaceState() method is as follows: window.history.replaceState(stateObj, title, url) Parameters ...
Read MoreHow to get image data url in JavaScript?
To obtain an image data URL in JavaScript, you can use several approaches depending on your source. The most common methods involve the Canvas API's toDataURL() method and the FileReader API for uploaded files. Using Canvas toDataURL() Method The toDataURL() method converts canvas content into a base64-encoded data URL. By default, it creates a PNG image, but you can specify JPEG format and quality. canvas.toDataURL(); // PNG format (default) canvas.toDataURL('image/jpeg'); // ...
Read MoreConvert Image to Data URI with JavaScript
JavaScript provides several methods to convert images to Data URI (Base64) format. A Data URI is a string representation of an image that can be embedded directly in HTML or CSS. This tutorial covers two main approaches: using Canvas API for image URLs and FileReader API for local files. Method 1: Converting Image URL to Data URI Using Canvas This method uses the HTML5 Canvas API to convert an image from a URL to a Base64 Data URI string. Convert Image URL to Data URI ...
Read MoreHow to do string interpolation in JavaScript?
String interpolation in JavaScript is a process in which expressions and variables are embedded directly into strings. This is achieved using template literals (backticks) with placeholder syntax ${}, making code more readable and maintainable than traditional string concatenation. Template literals use backticks (`) instead of quotes and allow expressions to be embedded using ${expression} syntax. This enables dynamic content insertion, mathematical calculations, and complex expressions within strings. Syntax `string text ${expression} more text` The expression inside ${} can be variables, function calls, mathematical operations, or any valid JavaScript expression that returns a value. ...
Read MoreDifferent techniques for copying objects in JavaScript
In JavaScript, objects are collections of key-value pairs. The properties of the object are the keys and are denoted with strings. The value of the key is the value of the property of the given object. Types of Object Copying There are 2 types of copying objects: shallow copy and deep copy. Shallow Copy In shallow copy, an object is copied at the top level only. If the object contains nested objects, only the references are copied, not the actual nested objects. Example Following is an example of shallow copy using Object.assign(): ...
Read MoreDifference between .extend() / .assign() and .merge() in Lodash library.
The Lodash library is a JavaScript utility library that provides helpful functions for working with arrays, strings, objects, numbers, and more. This article compares three important object merging methods: Object.assign(), _.extend(), and _.merge(). The Object.assign() Method Object.assign() is a native JavaScript method that performs shallow copying of enumerable properties from source objects to a target object. It modifies the target object and returns it. Syntax Object.assign(target, source1, source2, ...) Example var employee = { emp_name: "Abdul Rawoof", company: "Tutorials Point", salary: 18000, ...
Read MoreWhat is the use of .stack property in JavaScript?
The .stack property in JavaScript provides detailed information about errors, including the error type, message, and call stack trace. It shows where the error occurred and the sequence of function calls that led to the error. The stack property is available on Error objects and contains a string representation of the stack trace. This is extremely useful for debugging as it shows the exact location and path of execution when an error occurs. Format of Error Stack The stack trace format typically displays: First line: Error type and message Subsequent lines: Function call stack with file ...
Read MoreHow many values does javascript have for nothing?
JavaScript has two primitive values that represent "nothing": null and undefined. Both indicate the absence of a meaningful value, but they have distinct purposes and behaviors. Undefined A variable is undefined when it has been declared but not assigned a value, or when a function doesn't explicitly return anything. JavaScript automatically assigns undefined in these cases. Example 1 - Variable Declaration When a variable is declared but not assigned a value: var str; console.log('The value of given variable is:', str); The value of given variable is: undefined Example 2 ...
Read MoreWhat is the most efficient way to deep clone an object in JavaScript?
In JavaScript, objects are reference types, meaning simple assignment creates a reference to the original object, not a copy. Deep cloning creates a completely independent copy with separate memory allocation for nested objects and arrays. Understanding Deep vs Shallow Cloning Shallow cloning copies only the top-level properties, while deep cloning recursively copies all nested objects. Methods like spread operator and Object.assign() only perform shallow copies. Using JSON.parse() and JSON.stringify() (Most Common) The most efficient and widely-used approach combines JSON.stringify() to convert the object to a string, then JSON.parse() to create a new object from that string. ...
Read MoreHow to duplicate Javascript object properties in another object?
In JavaScript, objects are collections of key-value pairs where properties are identified by string keys. There are several ways to duplicate object properties from one object to another, each with different characteristics for handling nested objects and references. Using Spread Operator (...) The spread operator creates a shallow copy of an object by spreading its enumerable properties into a new object. It's represented by three dots (...) and is the most modern and readable approach. Example 1 This example demonstrates how the spread operator copies objects in JavaScript: var employee = { ...
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