单引号，双引号和无引号的Javascript正则表达式

Question

I have some html attributes that I would like to change based on different buttons being pressed. For instance, the width attribute will change. Im looking for a regex with Javascript that can replace the value within the attribute for single, double and no quotes.

width='200' , width="200" , width=200

EDIT

The reason im not using jQuery for instance to change the values, is because the element im trying to change, is the value inside of a textarea .

Quick example.

<textarea>
    <iframe width='200' height='200' />
</textarea>

I would like to change the value, of a value.

Answer 1

var regex = /(width=)(['"])?(\d+)(\2)/;
console.log('width="200"'.replace(regex, '$1$2555$4')); // width="555"
console.log("width='200'".replace(regex, '$1$2555$4')); // width='555'
console.log('width=200'.replace(regex, '$1$2555$4')); // width=555

Answer 2

"width='200', width=\"200\", width=200".replace(/(width=)(?:".*?"|'.*?'|\S*)/g, '$1"555"')
// => width="555", width="555", width="555"

But yeah, this is not a job for regexp.

Answer 3

Try this

[A-Za-z0-9-+]+=['"]{0,1}[^ ^"^']+['"]{0,1}

This matches a string followed by equal to, then 0 or 1 quotes followed by a string followed by 0 or 1 quote. its not perfect, it doesn't catch quotes inside the string