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In JavaScript, the getDay() method from the Date object returns the weekday as a number from 0 to 6, where Sunday is 0, Monday is 1, and so on. Syntax dateObject.getDay() The method returns an integer representing the day of the week: 0 = Sunday 1 = Monday 2 = Tuesday 3 = Wednesday 4 = Thursday 5 = Friday 6 = Saturday Example 1: Current Date Weekday Get the ... Read More
In JavaScript, you can access global variables dynamically using their name as a string through the window object (in browsers) or global object (in Node.js). Syntax // Browser environment window[variableName] // Node.js environment global[variableName] // Using globalThis (works in both) globalThis[variableName] Basic Example Dynamic Global Variables // Define global variables ... Read More
The "Not a constructor function" error occurs when we try to use the new keyword with a value that isn't a constructor function. This TypeError is thrown when JavaScript expects a constructor but receives a primitive value, object, or non-constructor function. What Causes This Error The error occurs when we attempt to instantiate something that cannot be used as a constructor: Primitive values (numbers, strings, booleans) Regular objects Arrow functions (in strict mode) Built-in methods that aren't constructors Example: Using Primitive as Constructor Constructor Error Demo ... Read More
We need to write a function that takes a string of number words as input and converts them into their equivalent whole number. Problem Overview Given a string containing number words separated by spaces, we want to convert each word to its corresponding digit and combine them into a single number. "one five seven eight" -------> 1578 "two eight eight eight" -------> 2888 Approach The solution involves creating a mapping of number words to digits, then iterating through each word to build the final number. We split the input string by whitespace ... Read More
We are required to write a JavaScript function that takes in a string and returns the count of redundant characters in the string. A redundant character is any character that appears more than once, where all duplicate occurrences (except the last one) are considered redundant. For example − If the string is − const str = 'abcde' Then the output should be 0 because each character appears only once. If the string is − const str = 'aaacbfsc'; Then the output should be 3 because 'a' appears 3 times (2 ... Read More
We are required to write a JavaScript function that takes in a string and checks whether it is sorted or not. A string is considered sorted if its characters are arranged in either ascending or descending order. For example: isSorted('adefgjmxz') // true (ascending) isSorted('zxmfdba') // true (descending) isSorted('dsfdsfva') // false (mixed order) Method 1: Character by Character Comparison This approach compares adjacent characters and tracks whether the string is ascending or descending: const str = 'abdfhlmxz'; const findDiff = (a, b) => a.charCodeAt(0) - b.charCodeAt(0); ... Read More
To append an item to a JavaScript array, you can use several methods. The most common approach is the push() method, which adds elements to the end of an array. Using push() Method The push() method adds one or more elements to the end of an array and returns the new length: var arr = ["marketing", "technical", "finance", "sales"]; arr.push("HR"); ... Read More
JavaScript does not support function overloading like other programming languages such as Java or C++. When you define multiple functions with the same name, JavaScript keeps only the last defined function. What Happens with Same Function Names Let's see what happens when we define multiple functions with the same name: function funcONE(x, y) { return x * y; } function funcONE(z) { return z; } // Only the last function definition is kept console.log(funcONE(5)); // prints 5 console.log(funcONE(5, 6)); // prints ... Read More
To set the distance between lines in text, use the lineHeight CSS property via JavaScript. This property controls the vertical spacing between lines of text within an element. Syntax element.style.lineHeight = value; The lineHeight value can be: Number: Multiplier of font size (e.g., "2" = 2x font size) Pixels: Fixed height (e.g., "30px") Percentage: Relative to font size (e.g., "150%") Example: Setting Line Height with Button Click Line Height Demo ... Read More
You can capture a still frame from an HTML5 video player by drawing the current video frame onto a canvas element. This technique is useful for creating thumbnails, implementing pause screens, or saving video snapshots. How It Works The process involves using the drawImage() method to copy the current video frame to a canvas. The canvas acts as a snapshot buffer that can be manipulated or saved. Example Your ... Read More