Concatenation char and int

Question

i've an error here , and couldn't solve it :

String generate_card (String Fname , String Lname ,int  card_id   ){
    String cardId = null ;
    cardId = Fname.charAt(0) + Fname.charAt(0) + card_id++  ;

return  cardId;

}

Answer 1

I think this is in java,hence the charAt() method

the error here is that you didn't create a new string object,you just assigned it to null

you should have written the following in the second line:

String cardId = "";

Answer 2

Perhaps try

cardId =  Character.toString(Fname.charAt(0)) +  Character.toString(Fname.charAt(0)) + card_id++;

Java(I assume) can't concatenate two chars and an int.

Answer 3

The problem is that Java won't automatically convert from int to String. This is necessary because you're trying to assing a new value to the String cardId. You could use:

cardId = Fname.charAt(0).toString() + Fname.charAt(0).toString() + Integer.toString(card_id++);

Note: by Java conventions your variable names and parameters shouldn't start with a capital letter

Answer 4

i've found the answer :

String generate_card (String Fname , String Lname ,int  card_id   ){
    String cardId = null ;
    cardId = Fname.charAt(0) + Lname.charAt(0) + String.valueOf(card_id++ ) ;

return  cardId;

}