isUpperCase

Checks if a string contains at least one uppercase letter and no lowercase letters.

Syntax

isUpperCase(str: string): boolean

Parameters

Parameter	Type	Description
str	string	The string to be checked.

Returns

Type	Description
boolean	true if the string contains at least one uppercase letter and no lowercase letters, otherwise false.

Example

isUpperCase("ABC"); // true
isUpperCase("aBC"); // false
isUpperCase("123"); // false
isUpperCase(""); // false

Notes

• Throws TypeError if the argument is not a string.
• Spaces are ignored in the check.

References

• MDN: Regular Expressions