And then we have a comparison operator which is " -ne" , for " non equal" .
然后我们有一个比较运算符“-ne”，表示“不等于”。
英语百科
Relational operator
（重定向自Comparison operator）
In computer science, a relational operator is a programming language construct or operator that tests or defines some kind of relation between two entities. These include numerical equality (e.g., 5=5) and inequalities (e.g., 4≥3).