Valid Number

 

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.

public boolean isNumber(String s) {
        if(s==null)
return false;
 
if(s.trim().isEmpty()){  
           return false;  
       }  
       String regex = "[-+]?(\\d+\\.?|\\.\\d+)\\d*(e[-+]?\\d+)?";  
       if(s.trim().matches(regex)){  
           return true;  
       }else{  
           return false;  
       }  
    }