方括号组和逗号的正则表达式 javascript

Question

I'm trying to construct a regular expression which I can use to replace all instances of "],[" with just "," in a string.

I'm stuck on this.

I've been through a number of different combinations - currently trying:

str.replace(/(\[,\])/, ',');

But it's not picking it up and I can't see what's wrong with it - anything obvious I'm doing wrong here?

Thanks

Answer 1

You are using the brackets in wrong order and you need to match multiple occurrences with the g flag.

So you may use

text = text.replace(/],\[/g, ',')

Or, if you want to use a capturing group,

text = text.replace(/](,)\[/g, '$1')

See regex demo #1 and regex demo #2 .

NOTE : If there may be any amount of whitespace between the brackets, use \s* to match it, eg text = text.replace(/]\s*,\s*\[/g, ',') .

JS demo:

 var text = "text],[text2],[text3"; console.log(text.replace(/],\[/g, ',')); console.log(text.replace(/](,)\[/g, '$1'));

Answer 2

Your square brackets are positioned wrongly, and you don't need the normal brackets.

Let's go in steps:

1. You want to replace all intances of ],[ so you need to use the following:

/],[/g

The g in the regexp is ensures that all instances are replaced.

2. [ and ] are special characters, so you use \ to stop regexp from parsing them:

/\],\[/g

Final Result:

 let str = '[myString],[AnotherString]'; str = str.replace(/\],\[/g, ","); console.log(str);