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// Slower (the zero-based :even selector is a jQuery extension)

$( "#my-table tr:even" );

// Better, though not exactly equivalent

$( "#my-table tr:nth-child(odd)" );

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$( ".data table.attendees td.gonzalez" );

// Better: Drop the middle if possible.

$( ".data td.gonzalez" );

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// Fast:

$( "#container div.robotarm" );

// Super-fast:

$( "#container" ).find( "div.robotarm" );

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// Unoptimized:

$( "div.data .gonzalez" );

// Optimized:

$( ".data td.gonzalez" );

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$( ".buttons > *" ); // Extremely expensive.

$( ".buttons" ).children(); // Much better.

$( ":radio" ); // Implied universal selection.

$( "*:radio" ); // Same thing, explicit now.

$( "input:radio" ); // Much better.