Use the concept of freeze() from JavaScript to disallow adding new properties to an object, altering of object properties, etc.Following is the code wherein we are changing the value but the previous value still remains since we cannot alter properties using freeze() −Exampleconst canNotChangeTheFieldValueAfterFreeze = {value1 : 10, value2: 20 ... Read More

Let us first create a nested object −var details = {    "teacherDetails":    {       "teacherName": ["John", "David"]    },    "subjectDetails":    {       "subjectName": ["MongoDB", "Java"]    } }Let us now extract the keys. Following is the code −Examplevar details = {   ... Read More

To set sleep i.e. delay, use the concept of setTimeout(). It takes values in milliseconds i.e.1000 milliseconds = 1 second 2000 milliseconds = 2 seconds, etc.For our example, we will add two values with a delay of 5 seconds i.e. 5000 milliseconds. Following is the code −Examplevar firstValue=10; var secondValue=20; ... Read More

To get largest numbers passed using reduce(), use the Math.max() function. Following is the code −const getBiggestNumberFromArraysPassed = allArrays => allArrays.reduce( (maxValue, maxCurrent) => maxValue.push(Math.max(...maxCurrent)), maxValue), []); console.log(getBiggestNumberFromArraysPassed([[45, 78, 3, 1], [50, 34, 90, 89], [32, 10, 90, 99]]));To run the above program, you need to use the following command ... Read More

Let’s say the following are our two strings −var originalName = "JOHNDOE"; var removalName = "JOHN"We need to remove the second string from first. For this, use replace() along with reduce().Exampleconst removeCharactersFromAString= (removalName, originalName)=>removalName.split('').reduce((obj, v)=>obj.replace(v, ''), originalName); var originalName = "JOHNDOE"; var removalName = "JOHN" console.log(removeCharactersFromAString(removalName, originalName));To run the above ... Read More

To un-nest array of objects, use the concept of map(). Let’s say the following are our array of objects −const studentDetails = [    {       "studentId": 101,       "studentName": "John",       "subjectDetails": {          "subjectName": "JavaScript"       } ... Read More

To fetch the highest value, use the Math.max() from JavaScript. Since, we want the one with maximum value, use the Object.values.Exampleconst studentMarksDetails= {    marks1:78,    marks2:69,    marks3:79,    marks4:74 } const maximumMarks = Math.max(...Object.values(studentMarksDetails)); console.log("The highest marks="+maximumMarks); for (const key of Object.keys(studentMarksDetails)){    if (studentMarksDetails[key] == maximumMarks) { ... Read More

To remove extra spaces, you need to use trim() along with regular expressions. Following is our string with spaces before applying trim() −var sentence="My name is John Smith ";Now, we will remove the extra spaces as in the below code −Examplevar sentence="My name is John Smith "; console.log("The actual value="); ... Read More

In order to modify the key values, you need to use regular expressions along with Object.fromEntries().Examplevar underscoreSpecifyFormat = str => str.replace(/(_)(.)/g, (_, __, v) => v.toUpperCase()), JsonObject = { first_Name_Field: 'John', last_Name_Field: 'Smith'}, output = Object.fromEntries(Object.entries(JsonObject).map(([key, value]) => [underscoreSpecifyFormat(key), value])); console.log("The JSON Object="); console.log(output);To run the above program, you need ... Read More

To remove ‘0’. ‘undefined’ and empty values, you need to use the concept of splice(). Let’s say the following is our array −var allValues = [10, false, 100, 150 ,'', undefined, 450, null]Following is the complete code using for loop and splice() −Examplevar allValues = [10, false, 100, 150 ,'', ... Read More