Javascript variables: Difference between revisions
From wikinotes
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var foo = "bar" // declare/assign variable (execute context scoped) | var foo = "bar" // declare/assign variable (execute context scoped) | ||
let foo = "bar" // declare/assign variable (block scoped) | let foo = "bar" // declare/assign variable (block scoped) | ||
var foo = (foo === undefined) ? "default" : foo // assign if undefined | |||
</source> | </source> | ||
</blockquote><!-- Declaration & Assignment --> | </blockquote><!-- Declaration & Assignment --> |
Revision as of 22:20, 9 September 2021
Variable Scope
execute-context-scoped: # variable scoped to function, or module if not defined in function block-scoped: # variable scoped to the { ... } contents
Declaration & Assignment
var foo // declare var (execute-context-scoped) let foo // declare var (block-scoped) const foo // declare constant (read-only) (block scoped) var foo = "bar" // declare/assign variable (execute context scoped) let foo = "bar" // declare/assign variable (block scoped) var foo = (foo === undefined) ? "default" : foo // assign if undefined