can we get sorted grep output

I have same: 1.txt with apple written in it, 2.txt with mango written in it, 3.txt with apple written in it, 4.txt with mango written in it.

grep -e apple -e mango *.txt will give result as:

1.txt: apple
2.txt: mango
3.txt: apple
4.txt: mango

But I need output as:

1.txt: apple
3.txt: apple
2.txt: mango
4.txt: mango

Is it possible with just grep command ? -- without using any other command like sort or so