How Android Intent putExtra() work? Under the hood …

Today we will discuss some basic points about intent putExtra(), How internally it works, and which data structure is used for it?

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val intent = Intent(this, SecondActivity::class.java)
intent.putExtra("k","v")
startActivity(intent)

1. When we write intent.putExtra(“k”,”v”) and click on this function

public @NonNull Intent putExtra(String name, @Nullable String value) {
    if (mExtras == null) {
        mExtras = new Bundle();
    }
    mExtras.putString(name, value);
    return this;
}

we see that it creates a Bundle object and adds it into mExtras.putString(name, value); and mExtras which is a bundle object, defines the global of the Intent class

Bundle mExtras;

after this we see mExtras.putString(name, value); is used to store name values,

when we click on mExtras.putString(name, value);

public void putString(@Nullable String key, @Nullable String value) {
    unparcel();
    mMap.put(key, value);
}

here we observe mMap.put(key, value); and mMap is ArrayMap<K,V> data structure that is designed to be more memory efficient than the traditional HashMap<K,V>

ArrayMap<String, Object> mMap = null;

Points To Remember

1. The Bundle object is created when putExtra() is used.
2. Internally ArrayMap<K,V> data structure is used to store data.

Kindly clapping …

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Kamal Kakkar - Software Engineer - KareXpertTechnologies Pvt Limited | LinkedIn

Thanks for reading, and I'll come again with new learnings soon