java - if 语句中线程 "main"java.util.NoSuchElementException 中出现异常

Question

这个问题已经有答案了:

Scanner NoSuchElementException when calling .next() method (3 个回答)

已关闭 5 年前。

if (charIte.next()=='{' || charIte.next()=='}'
                || charIte.next()=='[' || charIte.next()==']' 
                || charIte.next()=='(' || charIte.next()==')'
                || charIte.next()=='*' || charIte.next()=='"' 
                || charIte.next()=='/'){
}

程序返回:

Exception in thread "main" java.util.NoSuchElementException at line
|| charIte.next()=='(' || charIte.next()==')'

问题是什么？

Answer 1

每次调用 next() 都会消耗一个 token 。调用一次，保存后与结果进行比较。就像，

char ch = charIte.next();
if (ch == '{' || ch == '}' || ch == '[' || ch == ']' || ch == '(' 
            || ch == ')' || ch == '*' || ch == '"' || ch == '/') {
    // ...
}