使用变量替换所有出现的特定字符串

Question

How do I use a dynamic variable as first argument in replace function?

I have this code that searches a user specified string:

 var query = jQuery.trim(jQuery(this).val()).toLowerCase();
 console.log(query + ' was searched')
 jQuery('.one-reference').each(function () {
    var jQuerythis = jQuery(this);
    if (jQuerythis.text().toLowerCase().indexOf(query) === -1) {
       jQuerythis.fadeOut();
    }
    else {
       jQuerythis.html(jQuerythis.html().replace(/&/g, '<strong>$&</strong>'));
       jQuerythis.fadeIn();
    }
 });

This replace(/&/g, '<strong>$&</strong>')) is not working.

I want to wrap all occurrences of query with <strong> tags.

Answer 1

As you're searching for an arbitrary value within the html you will need to create a RegExp object and use that in your replace .

if (jQuerythis.text().toLowerCase().indexOf(query) === -1) {

  jQuerythis.fadeOut();
} else {
  var queryReg = new RegExp(query, 'g');
  jQuerythis.html(jQuerythis.html().replace(queryReg, '<strong>$&</strong>'));
  jQuerythis.fadeIn();
}

Also you will first need to escape ( \\ ) any characters in your query variable that have a special meaning in regular expressions ( ^$[]+()\\/- for example) -

query = query.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');

(from MDN )

See Regular Expressions at Mozilla Developer Network for a more in depth discussion on regular expressions.