Regular expression to get a class name from html

Question

I know my question might look like a duplication for this question, but its not
I am trying to match a class name inside html text that comes from the

Answer 1

Test it here: https://regex101.com/r/vnOFjm/1

regexp: (?:class|className)=(?:["']\W+\s*(?:\w+)\()?["']([^'"]+)['"]

const regex = /(?:class|className)=(?:["']\W+\s*(?:\w+)\()?["']([^'"]+)['"]/gmi;
const str = `



  





`;

let m;

while ((m = regex.exec(str)) !== null) {
    // This is necessary to avoid infinite loops with zero-width matches
    if (m.index === regex.lastIndex) {
        regex.lastIndex++;
    }
    
    // The result can be accessed through the `m`-variable.
    m.forEach((match, groupIndex) => {
        console.log(`Found match, group ${groupIndex}: ${match}`);
    });
}