StaffString
Valid Number
Given a string s, determine if it represents a valid number.
A valid number can be described by the following rules:
- It may be an integer or a decimal number.
- It may have an optional sign, either
+or-, at the beginning. - It may contain an exponent part, indicated by
eorE, followed by an integer.
An integer is defined as an optional sign followed by one or more digits.
A decimal number is defined as an optional sign followed by one of the following:
- One or more digits followed by a dot
.. - One or more digits followed by a dot
.followed by one or more digits. - A dot
.followed by one or more digits.
The exponent part, if present, must contain e or E followed by an integer.
Return true if s is a valid number, otherwise return false.
Example 1
Input
s = "0"Output
true0 is an integer, so it is a valid number.Example 2
Input
s = "e"Output
falsee does not contain a valid integer or decimal number before the exponent marker.Constraints
- 1 <= s.length <= 20
- s consists of only English letters (both uppercase and lowercase), digits (0-9), plus '+', minus '-', or dot '.'.