what is the integer that return by getInt(string key) in android.os.Bundle?

Question

i read document about getInt() method :

public int getInt (String key)

Returns the value associated with the given key, or 0 if no mapping of the desired type exists for the given key.

Parameters:

key a string

return:

an int value

but i can't get it that what it exactly return.

the ID of key that is in R.java or no something else???

Answer 1

It returns whatever you've put in that bundle with the same key.

Bundle bundle = new Bundle();
bundle.putInt("KEY", 1);
int value = bundle.getInt("KEY"); // returns 1

It's simply a map/dictionary datatype where you map a string value with something else. If you have other datatypes, you should use the appropriate put/get-methods for that datatype.

Answer 2

Nothing better that with an example

Suppose you have two activities: Activity1 and Activity2 and you want to pass data beetwen then:

Activity1

private static final String MY_KEY = "My Key"
Intent intent = new Intent(Activity1.this, Activity2.class);
Bundle b = new Bundle();

b.putInt(MY_KEY, 112233);

intent.putExtras(b);

startActivity(intent);

Activity 2

private static final String MY_KEY = "My Key"
Bundle b = getIntent().getExtras();

int value = b.getInt(MY_KEY , 0);

//value now have the value 112233

What means "Returns the value associated with the given key, or 0 if no mapping of the desired type exists for the given key." in this example?

Using Bundle you're sending the value 112233 from Activity 1 to Activity 2 using the key "MY_KEY". So, "MY_KEY" is associated with 112233.

As you can see there is a second parameter “0”.

It is the default value. In situation when Bundle doesn’t contains data you will receive “0” (default value).