JavaScript中全局正则表达式匹配的干净数组销毁

Question

This is more out of curiosity than anything else, but is there a clean method of looping over the matches of a global regex and destructuring each match in one line? The cleanest approach I can think of is:

 let regex = /(a)(b)?(c*)/g, str = 'cabcccaccaaabbacb', match, a, otherCaptures; while (([match, a, ...otherCaptures] = regex.exec(str) || []).length) { // do stuff console.log(match, a, otherCaptures); } 

If you don't include the || [] || [] , it tries to destructure null which throws an error. The empty array is truthy, so the best method I can think of is to check its length. Since you can't wrap a let statement in parentheses and then call a member of it, the variable declaration needs to happen outside the scope of the while which is undesirable.

Ideally there'd be a clever way to avoid the || [] || [] , but I haven't thought of one, short of adding a matches() member to RegExp.prototype (which might just be the ideal solution anyway).

Answer 1

Why not just destructure one line later:

 let part; 
 while(part = regex.exec(str)) {
   const [match, a, ...otherCaptures] = part;
   //...
 }

With a for loop the part can also be local scoped:

 for(let part; part = regex.exec(str); ) {
   const [match, a, ...otherCaptures] = part;
   //...
 }