What does the at symbol in javascript mean?

What does the at symbol in javascript mean?

decorator
The @ symbol in javascript stands for a decorator. Decorators are not present in ES6 so the in code you are working with the decorator is probably transpiled to an version of javascript which can be run in any browser.

What does AT SIGN mean in react?

It’s either a webpack alias you have set up to map @components to a local folder so you don’t have to do relative imports, or it’s an npm scope: docs.npmjs.com/misc/scope but scope seems less likely if it’s named “components”

Is ES7 a thing?

ES5 was published in 2009 and after that, the major release was ES6 in 2015, ES7 in 2016, Es8 in 2017, Es9 in 2018, Es10 in 2019.

What are ES7 features?

ES7 introduces a new mathematical operator called exponentiation operator. This operator is similar to using Math.pow() method. Exponentiation operator is represented by a double asterisk **. The operator can be used only with numeric values. The syntax for using the exponentiation operator is given below −

Why arrow functions are used?

Arrow functions introduce concise body syntax, or implicit return. This allows the omission of the curly brackets and the return keyword. Implicit return is useful for creating succinct one-line operations in map , filter , and other common array methods.

How do you use props?

How to use props in React

1. Step 1 – Pass in props as an argument. We did that in the first line of the code above: function Tool(props){} .
2. Step 2 – Declare props variable(s) const name = props.
3. Step 3 – Use variable(s) in JSX template.
4. Step 4 – Pass data to props in the App component.

Is ES7 supported?

Mozilla has some info on their website: it is possible to see that ES7 and ES8 are fully supported, ES9 still has some problems and ES10 is supported on the latest versions.

Which ES version should I use?

#Why you should use the highest possible version? Using the highest version allows you to write shorter code, and use more readable features, such as async/await, for..of, spread, etc. It’s not only shorter, but also easier to debug.

What’s new in ES7?

ES7 added an exponentiation operator (**) to already JavaScript supported arithmetic operations like +,-,*. This operator raises the first operand to the power second operand.

When you should not use the arrow function?

An arrow function doesn’t have its own this value and the arguments object. Therefore, you should not use it as an event handler, a method of an object literal, a prototype method, or when you have a function that uses the arguments object.

How do arrows work?

In short, with arrow functions there are no binding of this . In regular functions the this keyword represented the object that called the function, which could be the window, the document, a button or whatever. With arrow functions the this keyword always represents the object that defined the arrow function.

What is the latest version of ES?

ECMAScript