LeetCode每日一题：valid number

问题描述

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.

问题分析

这题我们可以用java自带的函数来判断，Double.valueOf(s)直接判断是不是数字，为了让函数能正常运行，用try catch方法来包裹函数。
要注意浮点数和double类型，最后不能出现f和d这样的符号。特别注意一下就好了，没什么很大的难度。

代码实现

public boolean isNumber(String s) {
        try {
            char c = s.charAt(s.length() - 1);
            if (c == 'f' || c == 'F' || c == 'd' || c == 'D') return false;
            Double.valueOf(s);
            return true;
        } catch (Exception e) {
            return false;
        }
    }