TypeError: String.prototype.matchAll called with a non-global RegExp argument (V8-based)TypeError: String.prototype.replaceAll called with a non-global RegExp argument (V8-based)TypeError: matchAll must be called with a global RegExp (Firefox)TypeError: replaceAll must be called with a global RegExp (Firefox)TypeError: String.prototype.matchAll argument must not be a non-global regular expression (Safari)TypeError: String.prototype.replaceAll argument must not be a non-global regular expression (Safari)

TheString.prototype.matchAll() andString.prototype.replaceAll() methods require aRegExp object with theglobal flag set. This flag indicates that the regular expression can match all locations of the input string, instead of stopping at the first match. Although theg flag is redundant when using these methods (because these methods always do a global replacement), they are still required to make the intention clear.

It's worth noting that theg flag validation is done in thematchAll andreplaceAll methods. If you use the[Symbol.matchAll]() method ofRegExp instead, you won't get this error, but there will only be a single match.

If you intend to do global matching/replacement: either add theg flag, or construct a newRegExp object with theg flag, if you want to keep the original regex unchanged.

[..."abc".matchAll(/./g)]; // [[ "a" ], [ "b" ], [ "c" ]]"abc".replaceAll(/./g, "f"); // "fff"const existingPattern = /./;const newPattern = new RegExp(  existingPattern.source,  `${existingPattern.flags}g`,);"abc".replaceAll(newPattern, "f"); // "fff"

If you only intend to do a single matching/replacement: useString.prototype.match() orString.prototype.replace() instead. You can also use the[Symbol.matchAll]() method if you want an iterator likematchAll returns that only contains one match, but doing so will be very confusing.

"abc".match(/./); // [ "a" ]"abc".replace(/./, "f"); // "fbc"[..././[Symbol.matchAll]("abc")]; // [[ "a" ]]

• String.prototype.matchAll()
• String.prototype.replaceAll()
• RegExp.prototype.global