在if语句中检查null是否在Java中不起作用

Question

Here is my if statement:

for(int i=0;i<SharedPrefsData.subscribers.length; i++){//loop through subscribers array
        if(SharedPrefsData.subscribers[i] == null ){//if string at index i is null
            SharedPrefsData.subscribers[i] = "";//make it empty string instead of null
        }

    }

I want it to loop through an array of strings and check if each element is null . My array is:

[name_1, null, null, null, null, null, null, null, null, null, null, null, null, null, null]

and yet it never enters the then part of my if statement. If anyone can help, it would be greatly appreciated.

My code that sets the array:

public static String[] getPrefs(){
    String[] ToReturn;
    String tempString = settings.getString("123", "0");
    if(tempString == "0"){
        //show some type of error
        ToReturn = null;
    } else {
        ToReturn = tempString.split("@,#");
    }
    return ToReturn;


}

And this is the statement that calls the method:

SharedPrefsData.setSubscribers(SharedPrefsData.getPrefs());

settings is a field in the same class of type SharedPreferences

Answer 1

The problem might be in the source of data

SharedPrefsData.subscribers array might have 'null' string instead of null. Just try

if(SharedPrefsData.subscribers[i] == null ||  SharedPrefsData.subscribers[i].equals("null"))

Again, the issue might be with the source and if the issue is resolved by above statement, you need to look at source and make sure it is not returning 'null' string in place of null object