Java (computing revision)

[Vasquez]

just wanted to check something,

would this work?

string forename = "john"
string surname = "smith"

username = forename.substrings(1, 3) + surname.substring(1, 3);

output would be johsmi?

its a question about string concatenation

 

[|Ric|]

Nope, output is "ohmi"

Strings start at 0 and the last index is exclusive (not inclusive)
http://java.sun.com/j2se/1.5.0/docs/api/java/lang/String.html#substring(int, int)

 

[Vasquez]

Nope, output is "ohmi"

Strings start at 0 and the last index is exclusive (not inclusive)
http://java.sun.com/j2se/1.5.0/docs/api/java/lang/String.html#substring(int, int)

ah cheers, so would it be (0, 2)?

 

[|Ric|]

For "johsmi" it would be (0,3)

3 Characters:
0 - 1st char (inclusive)
1 - 2nd char
2 - 3rd char
3 - 4th char (exclusive)

 

[RobH]

|Ric| is correct.

The substring begins at the specified beginIndex and extends to the character at index endIndex - 1. Thus the length of the substring is endIndex-beginIndex.

["j", "o", "h", "n"]
  ^    ^    ^    ^
  0    1    2    3

["s", "m", "i", "t", "h"]
  ^    ^    ^    ^    ^
  0    1    2    3    4

username = forename.substring(0, 3) + surname.substring(0, 3);

 

[Vasquez]

thanks guys!

 

[kidkoolio]

Surely you have access to a Java compiler?

How difficult would it have been to compile and run the code yourself to see the outcome?