如何比较一个字符以检查它是否为空？
问题描述：
我尝试了下面的内容，但Eclipse为此抛出了一个错误。
I tried the below, but Eclipse throws an error for this.
while((s.charAt(j)== null)
检查字符是否为 null ？
What's the correct way of checking whether a character is null?
答
检查字符串 s 不是 null 。 String＃charAt返回的字符是原始的 char 类型，永远不会是 null ：
Check that the String s is not null before doing any character checks. The characters returned by String#charAt are primitive char types and will never be null:
if (s != null) {
...
如果您尝试一次处理一个 String 中的字符，您可以使用：
If you're trying to process characters from String one at a time, you can use:
for (char c: s.toCharArray()) {
// do stuff with char c
}
（与 C 不同， NULL 终止符检查不是用Java完成的。）
(Unlike C, NULL terminator checking is not done in Java.)