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30 lines
661 B
30 lines
661 B
name: duk_has_var
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proto: |
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duk_bool_t duk_has_var(duk_context *ctx);
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stack: |
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[ ... varname! ] -> [ ... ]
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summary: |
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XXX
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<p>The identifier existence check does not have a direct Ecmascript equivalent.
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The closest equivalent is:</p>
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<pre class="ecmascript-code">
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typeof varname !== 'undefined'
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</pre>
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<p>However, if the identifier is defined but has the value <code>undefined</code>,
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the above check gives a different result than this API call. Note that the
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value of the identifier is not looked up and there can thus be no side effects
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from e.g. getter calls.</p>
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example: |
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XXX
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tags:
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- variable
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- omit
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introduced: 1.0.0
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