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The plus(+) sign before the variables defines that the variable you are going to use is a number variable.In the below code, there is brief description about plus sign. Following is the code −Examplevar firstValue="1000"; console.log("The data type of firstValue ="+typeof firstValues); var secondValue=1000; console.log("The data type of secondValue ="+typeof secondValue); console.log("The data type of firstValue when + sign is used ="+typeof +firstValue); var output=+firstValue + secondValue; console.log("Addition is="+output);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo149.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo149.js The data type ... Read More
The Bluetooth link layer outlines the way Bluetooth devices can use the raw transmission facility given by the radio layer to exchange information. The functions of the link layer is very close to MAC (medium access control) sublayer of the OSI model.The following diagram shows the position of link layers in the Bluetooth protocol architecture −Functions of the Bluetooth Link LayerDefining procedures for discovering Bluetooth devices.Establishing logical links between the Bluetooth devices that are communicating. One of the devices is assigned as master and the other is the slave.Broadcasting data to be sent. Managing the links between the devices throughout ... Read More
For this, you can use the concept of focus(). Following is the code −Example Live Demo Document Submit const submitButton = document.getElementById('submitBtn'); submitButton.addEventListener('click', () => { console.log('Submitting information to the server.....'); }) const txtInput = document.getElementById('txtInput'); txtInput.addEventListener('blur', () => { console.log('Enter the new value into the text box......'); txtInput.focus(); }); txtInput.focus(); To run the above program, save the file name “anyName.html(index.html)” and right click on the file. Select the option “Open ... Read More
To filter null from an array and display only non-null values instead, use filter(). Following is the code −Examplevar names=[null, "John", null, "David", "", "Mike", null, undefined, "Bob", "Adam", null, null]; console.log("Before filter null="); console.log(names); var filterNull=[]; filterNullValues=names.filter(obj=>obj); console.log("After filtering the null values="); console.log(filterNullValues);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo148.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo148.js Before filter null=[ null, 'John', null, 'David', '', 'Mike', null, undefined, 'Bob', 'Adam', null, null ] After filtering the null values= [ ... Read More
Let’s say the following is our object −const subjectDetails ={ 102:"Java", 105:"JavaScript", 104:"MongoDB", 101:"MySQL" };Use sort() method to retrieve object’s entry in order −const orderSubjects = Object.fromEntries(Object.keys(subjectDetails).sort().map((k) => { return [k, subjectDetails[k]]; }));Exampleconst subjectDetails ={ 102:"Java", 105:"JavaScript", 104:"MongoDB", 101:"MySQL" }; const orderSubjects = Object.fromEntries(Object.keys(subjectDetails).sort().map((k) => { return [k, subjectDetails[k]]; })); console.log(orderSubjects);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo146.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo146.js{ '101': 'MySQL', '102': 'Java', '104': 'MongoDB', '105': ... Read More
To print JSON nested object in JavaScript, use for loop along with JSON.parse(). Following is the code −Examplevar details = [ { "studentId": 101, "studentName": "John", "countryName": "US", "subjectDetails": "{\"0\":\"JavaScript\",\"1\":\"David\"}" }, { "studentId": 102, "studentName": "Bob", "countryName": "UK", "subjectDetails": "{\"0\":\"Java\",\"1\":\"Carol\"}" }, { "studentId": 103, "studentName": "Mike", "countryName": "AUS", "subjectDetails": "{\"0\":\"MongoDB\",\"1\":\"Adam\"}" } ] for (const detailsObject of details) { const subjectDetailsObject = JSON.parse(detailsObject.subjectDetails); console.log(subjectDetailsObject[0]); }To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo145.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo145.js JavaScript Java MongoDB
To get HTML form values, use the value property. Let’s say the following is our input type −We need to display the above value “My name is John Smith” on console.Example Live Demo Document var originalvalue = document.getElementById("getValues").value; console.log("The value in the text box is ="+originalvalue); To run the above program, save the file name “anyName.html(index.html)” and right click on the file. Select the option “Open with Live Server” in VS Code editor.OutputThis will produce the following output −
For this, use the concept of reduce(). Following is the code −Exampleconst subjectDetails = [ { subjectId: '101', subjectName: 'JavaScript' }, { subjectId: '102', subjectName: 'Java' }, { subjectId: '103', subjectName: 'JavaScript' } ]; console.log([...subjectDetails.reduce((obj1, obj2) => { if (obj1.has(obj2.subjectName)){ obj1.get(obj2.subjectName).frequency++; } else { obj1.set(obj2.subjectName, { subjectName: obj2.subjectName, frequency: 1 }); } return obj1; }, new Map()).values()]);To run the above program, you need ... Read More
To create, use add() method, whereas to delete created and appended element, you can use remove(). Following is the code −Example Live Demo Document Add A New Name AddName var givenName = document.querySelector('#name') var btnClass = document.querySelector('#addNameButton') var listOfName = document.querySelector('#listOfName') btnClass.addEventListener('click', () => { var actualName = givenName.value if (actualName.length != 0) { var createAnHTMLList = `${actualName}Remove Name` listOfName.innerHTML += ... Read More
Let’s get the current date first −var currentDate = new Date(); console.log("The current date is as follows="+currentDate);Now, let us remove seconds/ milliseconds by setting them to 0 using setSeconds() −currentDate.setSeconds(0, 0);Convert to ISO String using toISOString() −currentDate.toISOString()Let us now see the complete code with output −Examplevar currentDate = new Date(); console.log("The current date is as follows="+currentDate); currentDate.setSeconds(0, 0); console.log("After removing seconds from date, the new date is as follows="); console.log(currentDate.toISOString());To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo143.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo143.js The current date ... Read More