Syntax
The grammar of JavaScript.
DestructuringCompletion percentage: 96% (22814)Completion percentage: 96% (22814)
Completion percentage: 96% (22814)
Completion percentage: 96% (22814)
The destructuring assignment syntax is a JavaScript expression that makes it possible to unpack values from arrays, or properties from objects, into distinct variables.
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💡
The button at the top of each block lets you get the raw JSON data for any chart, or a GraphQL query you can run against our public API.
Spread OperatorCompletion percentage: 95.7% (22753)Completion percentage: 95.7% (22753)
Completion percentage: 95.7% (22753)
Completion percentage: 95.7% (22753)
Spread syntax (...) allows an iterable such as an array
expression or string to be expanded in places where zero or more arguments (for
function calls) or elements (for array literals) are expected, or an object expression
to be expanded in places where zero or more key-value pairs (for object literals) are
expected.
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Arrow FunctionsCompletion percentage: 95.5% (22695)Completion percentage: 95.5% (22695)
Completion percentage: 95.5% (22695)
Completion percentage: 95.5% (22695)
An arrow function expression is a compact alternative to a traditional
function
expression, but is limited and can't be used in all situations.
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We asked members of the JavaScript community to share their “pick of the year”
My 2020 Pick: A11y Coffee
This is a fantastic intro resource for learning about web accessibility! I picked it because it's our job as JS devs to make sure that the sites we build are usable by everyone, not just sighted keyboard-and-mouse users.
We asked members of the JavaScript community to share their “pick of the year”
Josh W. Comeau
Software-engineer-turned-educator
Nullish CoalescingCompletion percentage: 95.7% (22737)Completion percentage: 95.7% (22737)
Completion percentage: 95.7% (22737)
Completion percentage: 95.7% (22737)
The nullish coalescing operator (??) is a logical
operator that returns its right-hand side operand when its left-hand side operand is
null or undefined, and otherwise returns its left-hand side
operand.
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Optional ChainingCompletion percentage: 95.7% (22746)Completion percentage: 95.7% (22746)
Completion percentage: 95.7% (22746)
Completion percentage: 95.7% (22746)
The optional chaining operator (?.)
enables you to read the value of a property located deep within a chain of connected objects
without having to check that each reference in the chain is valid.
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Private FieldsCompletion percentage: 95.9% (22786)Completion percentage: 95.9% (22786)
Completion percentage: 95.9% (22786)
Completion percentage: 95.9% (22786)
Class fields are public by default, but private class members can be created
by using a hash # prefix. The privacy encapsulation of these class features is
enforced by JavaScript itself.
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Recommended Resources
Will Sentance
Professional JavaScript Learning Path
From JavaScript foundations, all the way to Hardcore Functional JavaScript, find out how far you can go with your JavaScript abilities in this comprehensive learning path.
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