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Question

I'm re-designing a mathematics program for students. The original program was written in adobe flash. This time I am doing it in PHP and JavaScript.

In the original program there are several XML files with hundreds of mathematical questions and some of which are fractions. Those fractions are written as: #(1,4). I want to make an function called # which can make classic fractions.

The problem: there is normal text around the #(1,3) and it is not separated with quotations. How can I let the browser know there is a function in the text? Example:

  <question>what is #(2,8) divided by #(3,4)</question>

I hope you know how to do this. Thanks.

Answer 1

Without more detailed information:

var s = "<question>what is #(2,8) divided by #(3,4)</question>";
var t = s.replace(/(^|\s|>)#\((\d+),(\d+)\)($|\s|<)/g, "$1<span class='fraction'><span class='numerator'>$2</span><span class='denominator'>$3</span></span>$4");

t is now

"<question>what is <span class='fraction'><span class='numerator'>2</span><span class='denominator'>8</span></span> divided by <span class='fraction'><span class='numerator'>3</span><span class='denominator'>4</span></span></question>"

So: regular expression where you find #(...,...) where the ... are numbers, and the "function" strings are either surrounded by white space, the start/end of the sentence, or angle brackets.

However, rewriting it to MathJax MathML or LaTeX format (http://mathjax.org) instead will look much nicer.