How to correctly pattern a regular expression?

Question

Regular Expressions

style="height:452px; width:1000px"
You need to remove the line height:452px; .and the size of the pixels can be any, tried like this
'/height:[0-9]{0-9999}px;/' but somehow it doesn't work

Answer 1

/height\s*:\s*[0-9]+px\s*;/
\s*is any number of whitespace characters (including zero). Just in case.
And you wrote the quantifier incorrectly, it should be at least like this: {0,9999}. Or rather, as I wrote above.