why can't i subtract strings

Question

//This work
System.out.println("abcd" + "efgh");

//This doesn't
System.out.println("abcdefgh" - "efgh");

let me know if anyone knows....!!

Answer 1

Davinder Kumar

You can solve your problem using StringBuilder like this

https://code.sololearn.com/c7RnV97Lff7F/?ref=app

Answer 2

Thats a special case.. Not in general arithmetic. What if "abcdefgh"-" efghi" ?

Addition happens because it does concatination.
Java has only one overload operator, that is plus (+) . It don't allow minus(-) operator on strings.. no any other arithmetic operations on strings..

Answer 3

Davinder Kumar You mean , the result you want by "abcdefgh" - "efgh" is "acbd"?

You can use replace method of String class like

System.out.print( "abcdefgh".replace("efgh",""));
//replaces "efgh" with empty string..

// syntax :
<original string>. replace( <replce new_substring>, <old sub_string> ) ;

Answer 4

How can you? What is the possible answer you expect in general?

Answer 5

Use split() string method maybe it's helpful to you

https://www.geeksforgeeks.org/split-string-java-examples/amp/

Answer 6

Davinder Kumar

Actually you are not subtracting, you are removing each character of 2nd string from 1st string but from backward side.

Answer 7

Output should be "abcd", just by subtracting method..!!!

Answer 8

You can write a customized method for subtracting a string after you detailed specify how it works / means.

Answer 9

AFAIK to this date there's no programming language that allows arithmetic operation with strings. But you're not the first to come up with that doubt

https://code.sololearn.com/ceF3uBMqFjTo/?ref=app

Answer 10

Davinder Kumar

I know your question but you cannot subtract string in any language only concatenation is possible so your requirement is different as I said you want to remove each character of 2nd string from 1st string in reverse order.

'A' - 'B' is possible because of subtraction of ASCII value but how you can expect "AB" - "A" = "B"

Answer 11

Davinder Kumar
Subtracting strings is more complicated than simple concatenation. Plus it is not very useful in real applications. But it makes for very interesting puzzle.😊
A͢J
Your solution was very similar to what I was trying privately. 😁
I did not post it because I was encountering inconsistent results I could not resolve.
I tweaked your code to illustrate them.
So far, I have not come up with a method on how to solve them..🤔

https://code.sololearn.com/c52o0rClVsCN/?ref=app

Answer 12

Sakshi what if i have different case

"AGGXTXAYB" - "GTAB" = AGXXY

Answer 13

Jayakrishna🇮🇳 ohk i got it that java does only support for + operator. Can you please tell any alternative way except split method....!!

Answer 14

Sakshi it works only for specific strings. Anyway Thanks ..!

Answer 15

Jayakrishna🇮🇳 sir it doesn't follow always consecutive patterns.

see this example. hope you get me now.!!

"AGGXTXAYB" - "GTAB" = AGXXY

Answer 16

Davinder Kumar Yes. You need find your own approach here.
Since , here you can use "regex" advancedly , for single character replace from a group of characters..

You need a loop for each single match replace. But see it replaces both "GG", not single "G" from your example , so you need stop condition. So i think entirely you need to define a method for this result. No predined ways available I think...

Answer 17

<DD> AB if we don't consider duplicates common...!

Answer 18

A͢J You are right sir but that isn't my question...!

Answer 19

Davinder Kumar see you can input the string and then use split () method, i already given the link now you can own make logic how to do it?