Lint modules on import (e.g. Fast Forward eLearning. 1) Which type of JavaScript language is ___. 16.9.1. 120) If the following lines of code differ, what is the difference? Developers | Designers | Data Scientists, Student Technical CommunityVIT Vellore, I manage Operations at Chingu, Inc. We help bridge what you have learned to get the experience employers seek. We can put any type in a variable. 16.9.2. As soon as a debugging session starts, the DEBUG CONSOLE panel is displayed and shows debugging output, and the Status Bar changes color (orange for default color themes): In addition, the debug status appears in the Status Bar showing the active debug configuration. Until Java SE 7, JDKs shipped with a JavaScript scripting engine based on Mozilla Rhino. Explanation: The method " Subtr()" in the javascript is used to return the characters in the string starting at the specified position via the specified number of the characters. Each platform keeps a default instance in the global variable System (the system loader), which implements its specific style of module loading. In CommonJS, they dont: a qualified import provides direct access to a property of a modules export object, an unqualified import is a copy of it. One common use of webpack is to prepare an application for production deployment. A function in JavaScript is similar to a procedurea set of statements that performs a task or calculates a value, but for a procedure to qualify as a function, it should take some input and return an output where there is some obvious relationship between the input and the output. When you open DevTools, you are simply attaching DevTools to your open browser tab. Similarly to AMD, they have direct support for asynchronous loading and configurable module loading. Create stunning courses in minutes. ), Public and private authentication keys (only secure in server applications). 139) Which of the following is not a JavaScript Data Types? This means instead of returning either true or false and it can be problematic because false-y can be either an empty string or can be 0. Inline breakpoints are shown inline in the editor. Normally we dont use it at all, but well cover subtle differences from let in the chapter The old "var", just in case you need them. in browsers). WebThe main difference between Global and local variables is that global variables can be accessed globally in the entire program, whereas local variables can be accessed only within the function or block in which they are defined. It provides better compliance with the ECMA normalized JavaScript specification and better runtime performance through invokedynamic-bound The default export is actually just a named export with the special name default. 13) Which of the following is the correct output for the following JavaScript code: Explanation: The "if-and if" statement is used to examine more than one condition. That means that even unqualified imports (such as bar in line ii and foo in line iv) are indirections that refer to the original data. You can see that export entries are set up statically (before evaluating the module), evaluating export statements is described in the section Runtime Semantics: Evaluation. Explanation: The variable's value will increase until it gets equal to 10, then the control will exit the loop's definition. On the other hand, if you come from a server or desktop background, it's quite normal to have your editor launch your process for you, and your editor automatically attaches its debugger to the newly launched process. On the other hand, you can list everything you want to export at the end of the module (which is similar in style to the revealing module pattern). Everything you read here may change. Answer: D: "Float" is the correct answer. GitBook. Explanation: The method "acos()" used in the above code returns the arccosine of any number passed in it as an argument. Explanation: The definition of any function always begins with a "keyword" function, followed by an identifier which is the name of the function as well as with a pair of parentheses that cover the list of identifiers. Answer: D: "All of the above" is the correct answer. Function expressions are sometimes defined and implemented immediately. WebMedical image segmentation is an important task for computer aided diagnosis. If possible, cyclic dependencies should be avoided, they lead to A and B being tightly coupled they can only be used and evolved together. Support for both synchronous and asynchronous loading, Support for cyclic dependencies between modules. Adding the .env file name to .gitignore prevents git push commands from uploading it to the GitHub repo where, for public repos, it would be available to anyone. let is a modern variable declaration. For example, the following tag starts a web application via a main module (the attribute name import is my invention, it isnt yet clear what name will be used). For the record, both frontend and backend applications may utilize dotenv. But, due to *default* not being a legal identifier, you cant access that binding from inside the module. 141) Which of the following function of the Array object is used to add one or more elements to the front of an array and returns the new length of the array? These limitations mean that both exporter and importers must be aware of cyclic dependencies and support them explicitly. It includes all the features from WebStorm, our IDE for JavaScript and related technologies. In general, we can say that all the closures are function or vice versa, and function has a scope chain associated with them. Explanation: Suppose a function that does not have a return statement in its definition returns a default value. JavaScript Style Guide. Alternatively, the action can be set to debugWithEdge or debugWithChrome. Thus, in the face of cyclic dependencies, it doesnt matter whether you access a named export via an unqualified import or via its module: There is an indirection involved in either case and it always works. WebAnswer: A Explanation: The strict comparison operator returns true only if the operand are of the same type and content matches. Using environment variables in backend applications relies on operating system commands to define the environment variable and its value. Two fundamental components of any computer programming language are variables and constants. No, you cant. Here are some more loops used in Javascript these days: For-in: For-in loop in JavaScript is used to iterate over the properties of an object. 9) What will happen, if the following JavaScript code is executed? They enable cyclic dependencies, even for unqualified imports (as explained in the next section). Post questions and get answers from experts. Expressions can be evaluated with the Debug Console REPL (Read-Eval-Print Loop) feature. IntelliJ IDEA Ultimate has got you covered! For example, fetch(process.env.REACT_APP_METEORITE_STRIKE_DATASET). Imports and exports must be at the top level, 16.3.5. Explanation: In JavaScript, the "Object.is() method is one of the built-in methods. It refers to those modules via. Explanation: In JavaScript, the reduce() method reduces the size of the array to a single value. 40) Which one of the following is correct output for the following given JavaScript code: Explanation: In the above given JavaScript code, the "in" operator is used which checks (or performs search) for the specific property. 86) Which one of the following options is the correct output for the given code of JavaScript? A system administrator may define these using a command line interface, but it typically makes more sense to do so via a shell script. For example, you can create a variable named first with a value of Nick with the following command: var first = 'Nick'; Once this variable has been created, you can print its value to the console of your web browser with the following JavaScript statement: console.log(first) Although webpack implements support for using environment variables its as an option of the webpack command. Declarative syntax (for importing and exporting), Programmatic loader API: to configure how modules are loaded and to conditionally load modules. In the first example, you have to run the code to find out what it imports: In the second example, you have to run the code to find out what it exports: ECMAScript 6 modules are less flexible and force you to be static. One such dialect is Low-Level JavaScript (LLJS). Explanation: In JavaScript, the "use strict" is not a keyword because it not includes any language keywords. Load modules synchronously, while the body is executed. The goal for ECMAScript 6 modules was to create a format that both users of CommonJS and of AMD are happy with: Being built into the language allows ES6 modules to go beyond CommonJS and AMD (details are explained later): There are two kinds of exports: named exports (several per module) and default exports (one per module). You can add a condition and/or hit count when creating a source breakpoint (with the Add Conditional Breakpoint action) or when modifying an existing one (with the Edit Condition action). The Reapply All Breakpoints command sets all breakpoints again to their original location. The answer is that you cant enforce a static structure via objects and lose all of the associated advantages (which are explained in this chapter). Explanation: The code given in the following question creates at least 10 closures, stores them as an array.Closures are all specified within the same function invocation, so they share access to the variable i.At the time of "constfun()" method returns 10 as the value of the variable i, all closures shares this value. JavaScript provides reasonable control to the users over the web browsers. Variables are a fundamental concept in any programming language. It also stores the value returned by the function in an accumulator, such as total or result. Due to this, understanding platform-specific factors is essential before using environment variables in your application. 108) Which one of the following options is the correct output for the given code of JavaScript? Come join us at Chingu.io to get out of Tutorial Purgatory by joining one of our remote Voyage project teams to build apps, refine hard skills, and learn new soft skills. Exports are managed via the data structure export entry. Explanation: The given pattern is applied on the string "text" enclosed in the parenthesis. WebRsidence officielle des rois de France, le chteau de Versailles et ses jardins comptent parmi les plus illustres monuments du patrimoine mondial et constituent la plus complte ralisation de lart franais du XVIIe sicle. In libraries, you can usually avoid cyclic dependencies via careful design. 134) Which of the following POSIX signals generate events? This is possible due to two characteristics of ES6 modules: As an example, consider the following two ES6 modules. For example. Imports are read-only views on exports, 16.4.2. Fast Forward eLearning. Explanation: Object.preventExtensions () only prevents adding new properties that have ever been added to an object. Optionally, breakpoints can be shown in the editor's overview ruler by enabling the setting debug.showBreakpointsInOverviewRuler: A Logpoint is a variant of a breakpoint that does not "break" into the debugger but instead logs a message to the console. JavaScript Literals The two most important syntax rules for fixed values are: 1. 147) What was the original name of JavaScript when it discovered? If the debugger extension you are using can run the debug target in VS Code's Integrated Terminal (or an external terminal), you can try to pass the shell redirect syntax (for example, "<" or ">") as arguments. Explanation: In the case, where the result of any arithmetic expression is beyond the largest represent-able number,JavaScript prints the infinity. 116) What will be the correct output of the following JavaScript code? 30) See the given code of JavaScript and choose the correct output from the following: Explanation: In JavaScript, the alert method does the typecasting and converts the value of the variable "valueinit" to a string after that it concatenates both of the strings and displayed them on the screen. Launch.json supports defining values (for example, arguments to be passed to the program) that depend on the operating system where the debugger is running. Hence the graphics generated in the dynamic manner from the real time data utilize the huge part of the CPU cycles. Another important point is that switch statements are also used as an alternative to "if-else" statements to reduce the complexity and size of the code. 36) Which one of the following operator is used to check weather a specific property exists or not: Explanation: In JavaScript, the "in" operator is used to check if a specific property exists. WebThe entire language is described here in detail. For example, the code snippets above are from an application generated by Create React App, which requires environment variables to be prefixed by REACT_APP_. In contrast, global variables are variables that are defined outside of functions. As a general rule, keep in mind that with cyclic dependencies, you cant access imports in the body of the module. 113) Which one of the following codes is correct for concatenating the strings passed into the function? Tip: Use the setting debug.toolBarLocation to control the location of the debug toolbar. WebA global variable has Global Scope: All scripts and functions on a web page can access it. 44) Which one of the following is correct output for the following given JavaScript code: Explanation: In the following code, the method "abs ()" is used which returns absolute numbers as output hence the correct option is c. In JavaScript, the "abs ()" method is one of the methods stored in the library called Math's. However, for most debugging scenarios, creating a launch configuration file is beneficial because it allows you to configure and save debugging setup details. Explanation: In general, each object contains three object associated attributes: Object prototype: It is kind of reference/indication to another object from which properties are inherited. operator, SyntaxError: redeclaration of formal parameter "x". However, there is an exception in JavaScript, dividing zero with zero will not have any defined number/value so, the result of this specific operation is a special value "Not a Number" (or NaN) and printed as NaN. JavaScript is a light-weighted and interpreted language. The const keyword was also introduced in the ES6(ES2015) version to create constants. That is what Node.js does. However, that is not a very strong recommendation; it occasionally may make sense to mix the two kinds. If you want to make sense of ECMAScript 6 modules, it helps to understand what goals influenced their design. You can either add all of the other modules exports: Default exports are ignored3 by export *. This is because it runs for the first time before checking the condition, and then executes until the condition becomes false. 72) Which one of the following is the correct output for the given JavaScript code? Can I use a variable to specify from which module I want to import? Explanation: The fundamental rule of lexical scoping is that: In the JavaScript, A function gets executed using the scope chain which was in effect, when they are defined. So, the "! The named launch configuration must be in the same file or folder as the one with the serverReadyAction. 19) When there is an indefinite or an infinite value during an arithmetic computation in a program, then JavaScript prints______. However, there are some differences between them. Variable names and values can be filtered by typing while the focus is on the VARIABLES section. In the dynamic scoping, it does not matter that how the code is written but what matters is how's the code executes. Can I import a module conditionally or on demand? ECMAScript 6 provides several styles of importing2: There are only two ways to combine these styles and the order in which they appear is fixed; the default export always comes first. The advantage of supporting modules in HTML via a custom