The JavaScript exceptions "unexpected token" occur when the parser does not see a token it recognizes at the given position, so it cannot make sense of the structure of the program. This might be a simple typo.

The JavaScript exception "await expression can't be used in parameter" or "yield expression can't be used in parameter" occurs when the default parameter expression contains the await or yield keyword and has the effect of pausing default parameter evaluation.

The JavaScript exception "variable is a reserved identifier" occurs when reserved keywords are used as identifiers.

The toLocaleString() method of BigInt values returns a string with a language-sensitive representation of this BigInt. In implementations with Intl.NumberFormat API support, this method simply calls Intl.NumberFormat.

# Contributors by commit history https://github.com/mdn/content/commits/main/files/en-us/web/javascript/reference/global_objects/bigint/index.md # Original Wiki contributors MadaraUchiha generalmim...

The reduce() method of Array instances executes a user-supplied "reducer" callback function on each element of the array, in order, passing in the return value from the calculation on the preceding element. The final result of running the reducer across all elements of the array is a single value.

The some() method of Array instances tests whether at least one element in the array passes the test implemented by the provided function. It returns true if, in the array, it finds an element for which the provided function returns true; otherwise it returns false. It doesn't modify the array.

The findIndex() method of Array instances returns the index of the first element in an array that satisfies the provided testing function. If no elements satisfy the testing function, -1 is returned.

# Contributors by commit history https://github.com/mdn/content/commits/main/files/en-us/web/svg/attribute/edgemode/index.md # Original Wiki contributors Sebastianz kydrost Jeremie 182

# Contributors by commit history https://github.com/mdn/content/commits/main/files/en-us/web/svg/attribute/end/index.md # Original Wiki contributors mfuji09 VictorJanin Sebastianz Jeremie 189