如何更改语法中的字段？

Question

TreeMap <String,Integer> H = new TreeMap <String,Integer>();

如果我在 Integer 的地方使用 Long 它会给出错误！

如何处理？

Answer 1

您可以将 Integer 替换为 Long 为：TreeMap<String,&nbsp;Long>&nbsp;H&nbsp;=&nbsp;new&nbsp;TreeMap<String,&nbsp;Long>();或者TreeMap<String,&nbsp;Long>&nbsp;H&nbsp;=&nbsp;new&nbsp;TreeMap<>();如果我们像下面这样声明，那么我们将得到 Type mismatch: cannot convert from specific Type to Specific Type 错误。TreeMap<String,&nbsp;Long>&nbsp;H&nbsp;=&nbsp;new&nbsp;TreeMap<String,&nbsp;Integer>();在这里我们会得到 Type mismatch: cannot convert from TreeMap to TreeMap。TreeMap<String,&nbsp;Integer>&nbsp;H&nbsp;=&nbsp;new&nbsp;TreeMap<String,&nbsp;Long>();这里我们会得到 Type mismatch: cannot convert from TreeMap to TreeMap