Java Programming - Java.lang Class - Discussion

The output of this code would be "ape", because:

The variable `a` is initialized with the string "newspaper".
The `substring()` method is used to extract a new string from `a` starting at index 5 (inclusive) and ending at index 7 (exclusive). This results in the string "ap".

The 'charAt()' method is used to retrieve the character at index 1 of the string "ap", which is the character 'p'.
The variable 'b' is assigned the value of 'p'.
The string concatenation operator `+` is used to concatenate the string "ap" and the character 'p', resulting in the string "ape".
Finally, the 'println()' method is used to print the value of the variable `a`, which is now "ape".

How is a.substring(5,7) same as a.substring(5,6)?

Execute it and see, following is the right answer, everything else is wrong.

a = a.substring(5,7) = n(0)e(1)w(2)s(3)p(4)a(5)p(6)e(7)r(8) = ape

It will take from 5th, 6th, and 7th position.

Then next,

a.charAt(1) = e

Final result = apep

That's it.

In string the position is starts from 0.

So count letters in "newspapers" as of a.substring(5,7); will count from 0 and its start taking letters after 5 till (7-1).

i.e till 6th letter.

So a.substring(5,7); will contains "ap"

Second argument of the Substring() method is the LENGTH from first argument.
a.Substring(5,7);//Returns:"aper"
a.charAt(1); // Returns: "p"
a = a + b; // a + b = ("aper" + "p") = "aperp"

a.substring(5,7); // Returns: "ap"

a.charAt(1); // Returns: "p"

a = a + b; // a + b = ("ap" + "p") = "app" stored in a.

Therefore the string "app" is the correct answer.

@Ahmed : as a.substring(5,7); // Returns: "ap"

So now a has "ap" that is a is in zero place and p in the 1 place.

So charAt(1) implies 1 place of a. that is p.

a.Substring(5,8);//Returns:"ape"(means 5,6,7)???
a.Substring(5,9);//Returns:"Aper"??? only 0 to 8 is available in string??

a.substring(5,7) will return ape.

So the final output should be apep...

Please explain why the first line is returning ap only and not ape.

a.substring (5, 7) will return ape.

And charAt (1) will be p. So answer will be apep.

How app anyone please explain?

substring(beginIndex, endIndex)

beginIndex - inclusive.
endIndex - exclusive.

That's why a.substring(5,7) = ap.