47 lines
1.2 KiB
Plaintext
47 lines
1.2 KiB
Plaintext
ECMAScript 2015 introduced the ``++let++`` and ``++const++`` keywords for block-scope variable declaration. Using ``++const++`` creates a read-only (constant) variable.
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The distinction between the variable types created by ``++var++`` and by ``++let++`` is significant, and a switch to ``++let++`` will help alleviate many of the variable scope issues which have caused confusion in the past.
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Because these new keywords create more precise variable types, they are preferred in environments that support ECMAScript 2015. However, some refactoring may be required by the switch from ``++var++`` to ``++let++``, and you should be aware that they raise ``++SyntaxError++``s in pre-ECMAScript 2015 environments.
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This rule raises an issue when ``++var++`` is used instead of ``++const++`` or ``++let++``.
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== Noncompliant Code Example
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[source,javascript]
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----
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var color = "blue";
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var size = 4;
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----
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== Compliant Solution
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[source,javascript]
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----
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const color = "blue";
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let size = 4;
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----
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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include::message.adoc[]
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include::highlighting.adoc[]
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'''
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== Comments And Links
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(visible only on this page)
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include::comments-and-links.adoc[]
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endif::env-github,rspecator-view[]
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