regex - How to convert 3 or more spaces to a hyphen conditionally in php -

i want convert multiple spaces hyphen.

for example, if there 3 or more consecutive spaces between words in string, want convert them hyphen.

original string :

 $x="hello    world! new        here.

string after execution:

 hello-world! new-here

i have tried following, not seem work properly.

 <?php  $str="hello    world! new     here";  echo preg_replace("/.*\s{3}/","-",$str);

please,try this:-

<?php $str="hello    world! new     here";  echo preg_replace("/\s{3,}/","-",$str); ?>

note: take care of number number of spaces equal or greater 3. thanks.

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