Loop to single statement

Question

In one of our applications we have the following lines:

while (text.indexOf(' ') !== -1)
    text = text.replace(' ', '_');
while (text.indexOf('*') !== -1)
    text = text.replace('*', 'x');

As far as I know I could also write it like this to avoid the loops:

text = text.replace(/ /g, '_');
text = text.replace(/*/g, 'x');

Which of the two versions would be better programming style? Is there any difference (performance, result, errors, ...) between these two? Do we have to avoid loops if possible?

Answer 1

I noticed that using regex somewhat confuses new (fresh/inexperienced) developers. So, they would find the first option easier to read and grasp what is it doing.

However, the second options is:

• Short and concise, also easy to read (provided, you are familiar with regex);
• Theoretically it should be faster, since you are letting the native code to do all the heavy lifting, instead of asking it to interpret the looping code an reassigning a string variable. However, the regex has some overhead that may lead to inefficiency. But, it does not apply (noticeable) in real life scenarios, especially in this case.

As for errors, it does not throw any errors, if you don't make any mistakes in your regex string. Ironically, you did (you should escape special character *). So, here is one reason for choosing option 1 :)

text.replace(/\*/g, 'x');

Answer 2

No brainer - your second option. Don't invoke a loop if you can avoid it. Javascript is a functional language; use it!

An even better solution is to chain them as follows:

text = text.replace(/ /g, "_").replace(/\*/g, "x");