The has() function of Map object accepts a key in string format and returns a boolean value, if specified key exists it returns true else returns false.SyntaxIts Syntax is as followsmapVar.has()Example Live Demo    JavaScript Example           var mapVar = new Map();       mapVar.set('1', 'Java');       mapVar.set('2', 'JavaFX');       mapVar.set('3', 'HBase');       mapVar.set('4', 'Neo4j');       document.write(mapVar.has('3'));     OutputtrueExample Live Demo    JavaScript Example           var mapVar = new Map();       mapVar.set('1', 'Java');     ... Read More

The get() function of Map object accepts a key in string format and returns its respective value.SyntaxIts Syntax is as followsmapVar.get()Example Live Demo    JavaScript Example           var mapVar = new Map();       mapVar.set('1', 'Java');       mapVar.set('2', 'JavaFX');       mapVar.set('3', 'HBase');       mapVar.set('4', 'Neo4j');       document.write(mapVar.get('3'));     OutputHBase

The forEach() function of Map object returns an iterator of the corresponding Map object and using this you can retrieve the key Value pairs of the map.SyntaxIts Syntax is as followsmapVar.forEach()Example Live Demo    JavaScript Example           var mapVar = new Map();       mapVar.set('1', 'Java');       mapVar.set('2', 'JavaFX');       mapVar.set('3', 'HBase');       mapVar.set('4', 'Neo4j');       function show(values) {          document.write(values);          document.write("");       }       mapVar.forEach(show);     OutputJava JavaFX HBase Neo4j

The clear() function of Map object removes all elements from the current Map object.SyntaxIts Syntax is as followsmapVar.clear()Example Live Demo    JavaScript Example           var mapVar = new Map();       mapVar.set('1', 'Java');       mapVar.set('2', 'JavaFX');       mapVar.set('3', 'HBase');       mapVar.set('4', 'Neo4j');       var map = mapVar.clear();       document.write("Size of the map object: "+mapVar.size);     OutputSize of the map object: 0Example Live Demo    JavaScript Example           var mapVar = new Map();       ... Read More

The size property of Map object accepts a JSON string, and constructs an object based on the given text and, returns it.SyntaxIts Syntax is as followsmapVar.sizeExample Live Demo    JavaScript Example           var mapVar = new Map();       mapVar.set('1', 'Java');       mapVar.set('2', 'JavaFX');       mapVar.set('3', 'HBase');       mapVar.set('4', 'Neo4j');       document.write("Size of the map object: "+mapVar.size);     OutputSize of the map object: 4

The set() function of Map object adds or updates elements (key-value pairs) to a Map object.SyntaxIts Syntax is as followsmapVar.set()Example Live Demo    JavaScript Example           var mapVar = new Map();       mapVar.set('1', 'Java');       mapVar.set('2', 'JavaFX');       mapVar.set('3', 'HBase');       mapVar.set('4', 'Neo4j');       document.write(mapVar.has('3'));     Outputtrue

The stringify() function of a JSON object accepts a JSON string, and constructs an object based on the given text and, returns it.SyntaxIts Syntax is as followsJson.stringify();Example Live Demo    JavaScript Example           var jsonSample = '{Tutorial: Java, Version:8}';       jsonObj = JSON.stringify(jsonSample);       document.write(jsonObj);     Output"{Tutorial: Java, Version:8}"

The JSON.parse() function accepts a JSON string, and constructs an object based on the given text and, returns it.SyntaxIts Syntax is as followsJson.parse();Example Live Demo    JavaScript Example           var jsonSample = '{"Tutorial": "Java", "Version":8 }';       jsonObj = JSON.parse(jsonSample);       document.write("Tutorial Name: " + jsonObj.Tutorial);       document.write("");       document.write("Tutorial Version: " + jsonObj.Version);     OutputTutorial Name: Java Tutorial Version: 8

Adding an element to an array can be done using different functions for different positions.Adding an element at the end of the arrayThis can be accomplished using the push method. For example, let veggies = ["Onion", "Raddish"]; veggies.push("Cabbage"); console.log(veggies);This will give the output −["Onion", "Raddish", "Cabbage"]You can also use this to push multiple items at the same time as it supports a variable number ofarguments. For example, let veggies = ["Onion", "Raddish"]; veggies.push("Cabbage", "Carrot", "Broccoli"); console.log(veggies);This will give the output −["Onion", "Raddish", "Cabbage", "Carrot", "Broccoli"]Adding an element at the start of the arrayThis can be accomplished using the unshift method. ... Read More

To create a collapsible list group, use the panel-collapse property with list-group property.ExampleThe list-group property lists items using the list-group-item property −Live Demo           Bootstrap Example                                          Questions/ Answers          Click below to learn about the technologies for which we provide Interview Questions.                                                                              Info                                                                                          Java                      PHP                      C++                      HTML5                      jQuery