javascript Regular Expression and Replace

Question

how can i replace

<em>Rs</em> 154,451. Hello world   

to

<b>Rs 154,451</b>. Hello world

via JavaScript Regular Expression.

/<em>Rs<\/em> [0-9,]*/ig

is regular expression to find <em>Rs</em> 154,451

Answer 1

You can use () to capture a match and later use it in the replace:

var s = "<em>Rs</em> 154,451. Hello world";
s.replace(/<em>Rs<\/em>([^.]+)/, '<b>Rs$1</b>')

Answer 2

Try this one:

myString = "<em>Rs</em> 154,451. Hello world";
output = myString.replace(/<em>Rs<\/em>\s*(\d+(?:,\d+)?)/g, "<b>Rs $1</b>");