正则表达式匹配整个字符串，但不区分大小写

Question

I have a list of codes that I loop through, and for each code I need to check for an exact but non-case sensitive match when a form is submitted.

I hva come up with a solution using a regular expression, but it's not quite perfect (it ignores case, but it will return partial matches).

For example, take this sample from my list of codes -

EXC
EXD
EXD1

If ex is submitted no matches should be found (but all 3 examples are matched), and if exd is submitted only EXD should be matched (but EXD1 is also matched).

In the code below val is the user input from the form and v.code is each looped code -

if(v.code.search(new RegExp(val, "i")) >= 0){ ...

How can I amend this code to meet my requirements? Thanks.

Answer 1

Build the regular expression with start and end anchors:

if (new RegExp("^" + val + "$", "i").test(v.code)) {
  // match!
}

If you're worried about performance should there be a whole lot of codes to test, you could pre-construct the regular expressions so that you don't have to do so for each validation.

Answer 2

You could do this without regex at all by:

if (val.toLowerCase() == "insensitive string".toLowerCase())
{
    // ...
}

Answer 3

使用单词边界：

new RegExp('\\b'+val+'\\b', "i")