RangeError: repeat count must be non-negative - JavaScript 编辑

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

Message

RangeError: argument out of range
RangeError: repeat count must be non-negative (Firefox)
RangeError: Invalid count value (Chrome)

Error type

RangeError

What went wrong?

The String.prototype.repeat() method has been used. It has a count parameter indicating the number of times to repeat the string. It must be between 0 and less than positive Infinity and cannot be a negative number. 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()