Cut a String After X Characters in JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:26:38

697 Views

To cut a string after X characters, use substr() function from JavaScript. Following is the JavaScript code wherein we are cutting the string after 9th character −Examplevar myName="JohnSmithMITUS"; console.log("The String="+myName) var afterXCharacter = myName.substr(0, 9) + "\u0026"; console.log("After cutting the characters the string="+afterXCharacter);Above, the unicode “\u0026” will replace all the characters with &(“\u0026”).To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo34.js.OutputThis will produce the following output.PS C:\Users\Amit\JavaScript-code> node demo34.js The String=JohnSmithMITUS After cutting the characters the string=JohnSmith&Read More

Finding Content of Arrays by Specific Property in JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:25:40

142 Views

For this, you can use find() along with a map(). Let’s say we have student records with name, rollno and subject.Examplevar firstObject= [    { "FirstName": "David", "RollNo": "105", "Subject": "MongoDB" },    { "FirstName": "Mike", "RollNo": "110", "Subject": "JavaScript"} ]; var secondObject= [    { "FirstName": "Bob", "RollNo": "101", "Subject": "Java" },    { "FirstName": "John", "RollNo": "110", "Subject": "MySQL" } ]; var output = firstObject.map(first=>(secondObject.find(second=>second.RollNo==first.R ollNo) || first)); console.log(output);To run the above program, you need to use the following command −node fileName.jsHere, my file name is demo33.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo33.js [   ... Read More

Separate Special Characters in JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:23:53

320 Views

To separate the special character, use the concept of match() with Regular Expression. The syntax is as follows −yourStringName.flatMap(anyVariableName => yourVariableName.match(/\w+|\W+/g));Let’s say, the following is our array with special characters in between values −var allNames = ['John-Smith', 'David', 'Carol%Taylor'];Let’s now see how to separate text with special characters. Following is the code −Examplevar allNames = ['John-Smith', 'David', 'Carol%Taylor']; var output = allNames.flatMap(obj => obj.match(/\w+|\W+/g)); console.log(output);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo32.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo32.js [    'John', '-',    'Smith', 'David',   ... Read More

Extract Text Value to a Variable Using JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:22:53

736 Views

To extract the value of the , use −document.getElementById(“yourTextIdValue”).textContentExample Live Demo Document This is the JavaScript....    var originalText = document.getElementById("myText").textContent;    console.log(originalText); To run the above program, just save the file name anyName.html(index.html) and right click on the file and select the option open with live server in VS Code editor.OutputThis will produce the following output display the value −

Check If String Begins with Punctuation in JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:14:53

709 Views

Let’s say we have the following strings. One of them is beginning with a question mark i.e. punctuation −var sentence1 = 'My Name is John Smith.' var sentence2 = '? My Name is John Smith.'We need to check whether any of the above two sentences begin with punctuation. To check if string begins with punctuation, the code is as follows −Examplevar punctuationDetailsRegularExpression=/^[., :!?]/ var sentence1 = 'My Name is John Smith.' var output1 = !!sentence1.match(punctuationDetailsRegularExpression) if(output1==true)    console.log("This ("+sentence1+") starts with a punctuation"); else    console.log("This ("+sentence1+") does not starts with a punctuation"); var sentence2 = '? My Name is ... Read More

Remove Whitespaces from a String Using Replace in JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:12:55

186 Views

Let’s say the following is our string with whitespace −var fullName=" John Smith ";Use replace() and set Regex in it to remove whitespaces.Examplefunction removeSpacesAtTheBeginningAndTheEnd(name) {    return name.toString().replace(/^\s+|\s+$/g,''); } var fullName=" John Smith "; var valueAfterRemovingSpace=removeSpacesAtTheBeginningAndTheEnd(fullName) console.log(valueAfterRemovingSpace);To run the above program, you need to use the following command −node fileName.js.Here my file name is demo208.js.OutputThis will produce the following output −PS C:\Users\Amit\javascript-code> node demo208.js John Smith

Best Way to Find Two Numbers in an Array Whose Sum is a Specific Number with JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:11:42

454 Views

Let’s say the following is our array −var numbers = [10, 3, 40, 50, 20, 30, 100]We need to search two numbers from the above array elements, whose sum is 80.For this, use simple for loop with if condition.Examplefunction specificPairsOfSumOfTwoNumbers(numbers, totalValue)    {       var storeTwoNumbersObject = {}       for(var currentNumber of numbers)       {          if(storeTwoNumbersObject[currentNumber])          {             return {                firstNumber: totalValue-currentNumber, secondNumber:currentNumber}             }         ... Read More

Get All Name-Values in a JSON Array using JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:09:07

4K+ Views

Let’s say the following is our JSON array −var details = [    {       "customerDetails": [             {                "customerName": "John Smith",                "customerCountryName": "US"             }       ]    },    {       "customerDetails": [          {             "customerName": "David Miller",             "customerCountryName": "AUS"          }       ]    },    { ... Read More

AddEventListener Not Working More Than Once with a Button in JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:05:13

2K+ Views

To make addEventListener() repeatedly work on button clicks, use the following code −Example Live Demo Document Click Me    var eventValue = function (event) {       document.body.appendChild(document.createElement('div'))       .textContent = event.type;    }    var pressed = document.querySelector("#pressButtonDemo");    pressed.addEventListener("click", eventValue); 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 −When you click the button “Click Me” then you will get ... Read More

Remove All Plus from Array in JavaScript

AmitDiwan
Updated on 01-Sep-2020 11:02:25

163 Views

Let’s say the following is our array with elements preceded by a + sign −var studentNames = [    '+John Smith',    '+David Miller',    '+Carol Taylor',    '+John Doe',    '+Adam Smith' ];To remove the + sign, the code is as follows −ExamplestudentNames = [    '+John Smith',    '+David Miller',    '+Carol Taylor',    '+John Doe',    '+Adam Smith' ]; console.log("The actual array="); console.log(studentNames); studentNames = studentNames.map(function (value) {    return value.replace('+', ''); }); console.log("After removing the + symbol, The result is="); console.log(studentNames);To run the above program, you need to use the following command −node fileName.js.Here my file ... Read More

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