maskString

Masks part of a string by replacing characters with a mask character.

Syntax

maskString(str: string, mask: string, maskStart: number, maskLength: number): string

Parameters

Parameter	Type	Description
str	string	The original string.
mask	string	The mask character or string.
maskStart	number	Starting index to apply the mask (>= 0).
maskLength	number	Number of characters to be masked (>= 0).

Returns

Type	Description
string	The resulting string with the masked part.

Example

maskString("123456789", "*", 2, 4); // "12****789"
maskString("abcdef", "#", 0, 3); // "###def"
maskString("openai", "X", 4, 10); // "openXX"

Notes

• Throws TypeError if the arguments are not of the expected type.
• Throws RangeError if maskStart or maskLength are negative, or if maskStart is greater than the string length.
• If maskLength exceeds the remaining length of the string, masks until the end.

References

• MDN: String.prototype.slice()
• MDN: String.prototype.repeat()