Live Demo: JavaScript RegExp to Replace All Words inside a String

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>JavaScript RegExp to Replace All Words inside a String</title>
</head>
<body>
    <h4>Original String</h4>
    <p>if the facts do not fit the theory, change the facts.</p>
    <h4>String After Replacement</h4>
    
    <script>
    /* Define function for escaping user input to be treated as 
       a literal string within a regular expression */
    function escapeRegExp(string){
        return string.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
    }
     
    /* Define functin to find and replace specified term with replacement string */
    function replaceAll(str, term, replacement) {
      return str.replace(new RegExp(escapeRegExp(term), 'g'), replacement);
    }
     
    /* Testing our replaceAll() function  */
    var myStr = 'if the facts do not fit the theory, change the facts.';
    var newStr = replaceAll(myStr, 'facts', 'statistics')
    
    // Printing the modified string
    document.write('<p>' + newStr + '</p>');
    </script>
</body>
</html>