The 'x' modifier is used for writing regular legibly by including spaces inside the regular expression, but it ignore ordinary white spaces.

u try this, 

$words_to_match = 'Hello\s+World';
$output_line = /$words_to_match/ix ;

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In reply to Re: disregard spaces while matching ? by murugu
in thread disregard spaces while matching ? by Anonymous Monk

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