Found 9150 Articles for Object Oriented Programming

ES6 Default Parameters in nested objects – JavaScript

AmitDiwan
Updated on 09-Nov-2020 09:06:58

574 Views

Yes, you can pass default parameters in nested objects.Following is the code −ExampleFollowing is the code −function callBackFunctionDemo({ cl: { callFunctionName = "callBackFunction", values = 100 } = {} } = {}) {    console.log(callFunctionName);    console.log(values); } //This will print the default value. // 100 callBackFunctionDemo(); //This will print the given value. //500 callBackFunctionDemo({ cl: { values: 500 } });To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo296.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo296.js callBackFunction 100 callBackFunction 500

How to decrease size of a string by using preceding numbers - JavaScript?

AmitDiwan
Updated on 09-Nov-2020 09:05:13

103 Views

Let’s say our original string is the following with repeated letters −var values = "DDAAVIDMMMILLERRRRR";We want to remove the repeated letters and precede letters with numbers. For this, use replace() along with regular expression.ExampleFollowing is the code −var values = "DDAAVIDMMMILLERRRRR"; var precedingNumbersInString = values.replace(/(.)\1+/g, obj => obj.length + obj[0]); console.log("The original string value=" + values); console.log("String value after preceding the numbers ="); console.log(precedingNumbersInString);To run the above program, you need to use the following command −node fileName.js. Here, my file name is demo295.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo295.js The original string value=DDAAVIDMMMILLERRRRR String value ... Read More

How to automate this object using JavaScript to set one key on each iteration as null?

AmitDiwan
Updated on 09-Nov-2020 09:03:13

170 Views

For this, use Object.keys() and set one key on each iteration as null using a for loop..ExampleFollowing is the code −var objectValues = {    "name1": "John",    "name2": "David",    "address1": "US",    "address2": "UK" } for (var tempKey of Object.keys(objectValues)) {    var inEachIterationSetOneFieldValueWithNull = {       ...objectValues,        [tempKey]: null    };    console.log(inEachIterationSetOneFieldValueWithNull); }To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo294.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo294.js { name1: null, name2: 'David', address1: 'US', address2: 'UK' ... Read More

Set the value in local storage and fetch – JavaScript?

AmitDiwan
Updated on 09-Nov-2020 09:00:59

593 Views

Use localStorage.setItem(“anyKeyName”, yourValue) to set the value in local storage and if you want to fetch value then you can use localStorage.getItem(“yourKeyName”)ExampleFollowing is the code − Live Demo            Document        var textBoxNameHTML = document.getElementById('txtName');    textBoxNameHTML.addEventListener('change', (e) => {       localStorage.setItem("textBoxValue", e.target.value);    }); To run the above program, save the file name “anyName.html(index.html)”. Right click on the file and select the option “Open with Live Server” in VS Code editor.OutputThis will produce the following output on console −Now, I ... Read More

How to sort array by first item in subarray - JavaScript?

AmitDiwan
Updated on 09-Nov-2020 08:57:52

526 Views

Let’s say we have the following array −var studentDetails = [    [89, "John"],    [78, "John"],    [94, "John"],    [47, "John"],    [33, "John"] ];And we need to sort the array on the basis of the first item i.e. 89, 78, 94, etc. For this, use sort().ExampleFollowing is the code −var studentDetails =    [       [89, "John"],       [78, "John"],       [94, "John"],       [47, "John"],       [33, "John"]    ]; studentDetails.sort((first, second) => second[0] - first[0]) console.log(studentDetails);To run the above program, you need to use the ... Read More

How to remove duplicate property values in array – JavaScript?

AmitDiwan
Updated on 09-Nov-2020 08:55:46

802 Views

Let’s say the following is our array −var details = [    {       studentName: "John",       studentMarks: [78, 98]    },    {       studentName: "David",       studentMarks: [87, 87]    },    {       studentName: "Bob",       studentMarks: [48, 58]    },    {       studentName: "Sam",       studentMarks: [98, 98]    }, ]We need to remove the duplicate property value i.e. 87 is repeating above. We need to remove it.For this, use the concept of map().ExampleFollowing is the code −var details ... Read More

Trigger an event IMMEDIATELY on mouse click, not after I let go of the mouse - JavaScript?

AmitDiwan
Updated on 09-Nov-2020 08:51:33

289 Views

For this, use the addEventListener() with mousedown event.ExampleFollowing is the code −            Document    document.addEventListener("mousedown", function () {       console.log("Mouse down event is happening");    }); To run the above program, save the file name “anyName.html(index.html)”. Right click on the file and select the option “Open with Live Server” in VS Code editor.OutputThis will produce the following output on console −When you click the mouse, the event will generate. The console output is shown below −

Add time to string data/time - JavaScript?

AmitDiwan
Updated on 09-Nov-2020 08:49:22

1K+ Views

At first, set a new Date in JavaScript −var dateValue = new Date("2021-01-12 10:10:20");Use new Date() along with setHours() and getHours() to add time.ExampleFollowing is the code −var dateValue = new Date("2021-01-12 10:10:20"); dateValue.setHours(dateValue.getHours() + 2); console.log("The date value is=" + dateValue.toString()); console.log("Only Hours value after incrementing=" + dateValue.getHours());To run the above program, you need to use the following command −node fileName.js. Here, my file name is demo291.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo291.js The date value is=Tue Jan 12 2021 12:10:20 GMT+0530 (India Standard Time) Only Hours value after incrementing=12Read More

How to generate array key using array index – JavaScript associative array?

AmitDiwan
Updated on 09-Nov-2020 08:47:57

342 Views

For this, use forEach() along with [] to an associative array.ExampleFollowing is the code −var result = {}; var names = ['John', 'David', 'Mike', 'Sam', 'Bob', 'Adam']; names.forEach((nameObject, counter) => {    var generatedValues = { [nameObject]: counter };    Object.assign(result, generatedValues) }) console.log(result);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo290.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo290.js { John: 0, David: 1, Mike: 2, Sam: 3, Bob: 4, Adam: 5 }

How do I change a tag's inner HTML based on their order in JavaScript?

Yaswanth Varma
Updated on 21-Apr-2023 17:01:34

681 Views

The innerHTML property of an element in JavaScript allows you to access or modify any HTML or XML markup that is there. Use the method insertAdjacentHTML () to insert HTML into the page as opposed to changing an element's content. In JavaScript to change a tag’s innerHTML based on their order can be done using document.querySelectorAll(). Let’s jump into the article to learn more about changing the tag’s innerHTML based on their order. Using document.querySelectorAll() The static NodeList returned by the Document function querySelectorAll() lists all of the document's elements that match the given set of selectors. Syntax Following is ... Read More

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