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38 lines
938 B
XML
38 lines
938 B
XML
<!DOCTYPE qhelp PUBLIC
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"-//Semmle//qhelp//EN"
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"qhelp.dtd">
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<qhelp>
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<overview>
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<p>
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Builtin functions and objects defined in the JavaScript standard library can be shadowed or redefined in user code.
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This is confusing and makes code hard to understand, so it should be avoided.
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</p>
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</overview>
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<recommendation>
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<p>
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Refactor the code to avoid shadowing or redefinition. For example, if a local variable has the same name as a standard
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library builtin, it should be renamed.
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</p>
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</recommendation>
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<example>
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<p>
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In the following example, the user-defined function <code>eval</code> shadows the builtin function <code>eval</code>
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defined in the standard library. It could be renamed <code>evaluate</code> to avoid confusion.
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</p>
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<sample src="examples/BuiltinRedefined.js" />
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</example>
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<references>
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<li>Ecma International, <i>ECMAScript Language Definition</i>, 5.1 Edition, Section 15. ECMA, 2011.</li>
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</references>
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</qhelp>
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