How to Fix "replaceAll called with a non-global RegExp argument" JavaScript Error?

Why Does This Happen?

When you use a regular expression pattern with the String.prototype.replaceAll() method without specifying the "g" (global) flag, it throws the following error:

// ES12+
const str = 'foo bar foobaz';
// Error: String.prototype.replaceAll called with a non-global RegExp argument
const newStr = str.replaceAll(/foo/, 'fox');
// ...

The reason this happens is that the global flag is required when using a regular expression with String.prototype.replaceAll(). Omitting the global flag results in a TypeError, as illustrated in the example above.

How to Fix the Issue?

To fix this issue, you need to simply include the global (g) flag with the regular expression. You can do so in the following two ways:

1. Using Literal Notation

   If you're using the literal regular expression notation, you can specify the global flag like so:

   // ES12+
   const str = 'foo bar foobaz';
   const newStr = str.replaceAll(/foo/g, 'fox');
   
   console.log(newStr); // 'fox bar foxbaz'
   

2. Using the RegExp() Constructor

   If you're using the RegExp() constructor, you can add the global flag in the following way:

   // ES12+
   const str = 'foo bar foobaz';
   const newStr = str.replaceAll(new RegExp('foo', 'g'), 'fox');
   
   console.log(newStr); // 'fox bar foxbaz'