复制ArrayList中的项(Duplication of an item in an ArrayList)

复制ArrayList中的项(Duplication of an item in an ArrayList)

我在我的ArrayList中存储标识地址。 问题是我反复存储它。

这是相关的代码：

public void storeIDs(final String emailAddress) { SharedPreferences.Editor editor = context.getSharedPreferences("storeIds", MODE_PRIVATE).edit(); IDAddresses.add(emailAddress); for(int i=0;i<IDAddresses.size();i++) { editor.putString("value"+i,IDAddresses.get(i)); } editor.putInt("emailListSize",IDAddresses.size()); editor.apply(); }

如何检查ArrayList IDAddresses是否已存在emailAddress ，如果存在，则不存储它？

I am storing Identification addresses in my ArrayList. The problem is I am storing it repeatedly.

Here is the relevant code:

public void storeIDs(final String emailAddress) { SharedPreferences.Editor editor = context.getSharedPreferences("storeIds", MODE_PRIVATE).edit(); IDAddresses.add(emailAddress); for(int i=0;i<IDAddresses.size();i++) { editor.putString("value"+i,IDAddresses.get(i)); } editor.putInt("emailListSize",IDAddresses.size()); editor.apply(); }

How do I check if the emailAddress already exists in the ArrayList IDAddresses and if it exists, then dont store it?

最满意答案

//use this : if( !IDAddresses.contains(emailAddress) ){ IDAddresses.add(emailAddress); } //instead of just this : IDAddresses.add(emailAddress); //use this : if( !IDAddresses.contains(emailAddress) ){ IDAddresses.add(emailAddress); } //instead of just this : IDAddresses.add(emailAddress);