I scraped webpage but it has a lot of special characters, for example,

"a +ΔS" turns into: "a +ΔS"

"→" turns into: "→"

"<−>" turns into: "<−>"

When I display it to my website.

I tried to change it manually to html numbers like "→" to "& rarr ;", but I feel like I am wasting my time because of too many occurences.

Why does his website reads "→" without converting to "& rarr ;"?

I tried this but did not work Thanks:

replace(/[\u00A0-\u9999<>\&]/g, function(i) {
   document.write('&#'+i.charCodeAt(0)+';');
});