how to replace last occurrence of a word in javascript?

Question

for example:

var str=\"
hi
hi\";

to replace the last(second)
,

to change into \"<

Answer 1

You can use the fact that quantifiers are greedy:

str.replace(/(.*)
/, "$1");

But the disadvantage is that it will cause backtracking.

Another solution would be to split up the string, put the last two elements together and then join the parts:

var parts = str.split("
");
if (parts.length > 1) {
    parts[parts.length - 2] += parts.pop();
}
str = parts.join("
");