The JavaScript exception "repeat count must be non-negative" occurs when theString.prototype.repeat() method is used with acountargument that is a negative number.

Message

RangeError: Invalid count value: -1 (V8-based)RangeError: repeat count must be non-negative (Firefox)RangeError: String.prototype.repeat argument must be greater than or equal to 0 and not be Infinity (Safari)

Error type

What went wrong?

TheString.prototype.repeat() method has been used. It has acount parameter indicating the number of times to repeat the string. Itmust be between 0 and less than positiveInfinity and cannot be a negativenumber. The range of allowed values can be described like this: [0, +∞).

Examples

Invalid cases

"abc".repeat(-1); // RangeError

Valid cases

"abc".repeat(0); // ''"abc".repeat(1); // 'abc'"abc".repeat(2); // 'abcabc'"abc".repeat(3.5); // 'abcabcabc' (count will be converted to integer)

See also

• String.prototype.repeat()