Validate if a given string is numeric.
Some examples:"0"
=> true
" 0.1 "
=> true
"abc"
=> false
"1 a"
=> false
"2e10"
=> true
Note: It is intended for the problem statement to be ambiguous. You should gather all requirements up front before implementing one.
Notice that "3." is a valid number, so the regular expression between two brackets should be \d*.
public class Solution { public boolean isNumber(String s) { return s.trim().matches("[-+]?(\d+\.?|\.\d+)\d*([eE][-+]?\d+)?"); } }