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Let’s say the following are our array of objects:const details = [ { employeeFirstName: "John", employeeLastName: "Doe" }, { employeeFirstName: "David", employeeLastName: "Miller" }, { employeeFirstName: "John", employeeLastName: "Smith" } ]ExampleFollowing is the code to fetch specific values, in this case with first name “John” −const details = [ { ... Read More
Let’s say the following is our array object −var arrayObject = [ "John", "David", "Mike" ]Use length property to set the length to 0 and clear memory.The syntax is as follows to clear memory and allocate again −yourArrayObjectName.length=0; // To clear memory yourArrayObjectName.length=4; // To allocate memoryExampleFollowing is the code −var arrayObject = [ "John", "David", "Mike" ] arrayObject.length = 0; console.log(arrayObject); arrayObject.length = 5; for (var i = 0; i < arrayObject.length; i++) console.log(arrayObject[i]);To run the ... Read More
To fetch alternative values, use the array index and check with the following condition −if(index%2==0) { // code } The above will display the even values.ExampleFollowing is the code −var subjectsName=["MySQL","JavaScript","MongoDB","C","C++","Java"]; for(let index=0;index node demo222.js Subject name at even position=MySQL Subject name at even position=MongoDB Subject name at even position=C++
Use get keyword to make getter function.ExampleFollowing is the code −const studentDetails = { studentName: "David Miller", get studentName() { console.log('I am calling the getter method...') } } console.log(studentDetails.studentName);To run the above program, you need to use the following command −The output is as follows −node fileName.js.Here, my file name is demo221.js.OutputThe output is as follows −PS C:\Users\Amit\JavaScript-code> node demo221.js I am calling the getter method... Undefined
For this, use the “this” keyword.ExampleFollowing is the code −class Employee { constructor() { this.tempObject = [ { firstName: "David", setTheAnotherFirstName() { this.firstName = "Carol"; }, }, ]; } } var empObject = new Employee(); empObject.tempObject[0].setTheAnotherFirstName(); console.log("The Change First Name is=" + empObject.tempObject[0].firstName);To run the above program, you need to use the following command −node fileName.js. Here, my file name is demo220.js.OutputThe output is as follows −PS C:\Users\Amit\JavaScript-code> node demo220.js The Change First Name is=Carol
To add property, use map(). Let’s say the following is our array −const firstname = ['John', 'David', 'Bob'];Following are our array of objects −const studentDetails = [ { firstname: 'Carol', marks: 78 }, { firstname: 'Mike', marks: 89 }, { firstname: 'Bob', marks: 86 } ]; ExampleFollowing is the code −const firstname = ['John', 'David', 'Bob']; const studentDetails = [ { firstname: 'Carol', marks: 78 }, { ... Read More
Let’s say we have the following variables −var value1 = 10; var value2 = 10.15;Use the Number() condition to check that a number is float or integer −Number(value) === value && value % 1 !== 0; }ExampleFollowing is the code −function checkNumberIfFloat(value) { return Number(value) === value && value % 1 !== 0; } var value1 = 10; var value2 = 10.15; if (checkNumberIfFloat(value1) == true) console.log("The value is float=" + value1); else console.log("The value is not float=" + value1); if (checkNumberIfFloat(value2) == true) console.log("The value is float=" + value2); else console.log("The value is not ... Read More
For ternary operator alternative, simply use if else in JavaScript. Let’s say, we have two numbers −var number1=12; var number2=12;To compare, we can use if else, instead of the ternary operator −if(number1==number2) console.log("true"); else console.log("false");ExampleFollowing is the code −var number1=12; var number2=12; var result=(number1==number2)?true:false; console.log(result); if(number1==number2) console.log("true"); else console.log("false");To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo217.js.OutputThe output is as follows −PS C:\Users\Amit\JavaScript-code> node demo217.js true trueRead More
To remove, use remove() and append() to add option in already created select list. Let’s say the following is our select − JavaScript MySQL ExampleFollowing is the code to remove all the options and add a new one − Live Demo Document JavaScript MySQL $('#demo') .find('option') .remove() .end() .append('MongoDB') .val('MongoDB') ; 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.OutputThe output is as follows −
Use tag for a new line.ExampleFollowing is the code − Document My Name is David Miller document.getElementById("headingDemo").innerHTML = "My Favourite Subject is JavaScript" + '' + "I live in AUS."; 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.The output is as follows −