java - Handling possibility of empty parseInt -

i have string, , extract text between 2 special characters.

(my text numbers, example -- hi%773%what -- 773)

i use praseint change substring of numbers integer(which successful).

where program crashes , burns (praseint numformat exception) , when string contains no numbers between special characters.

my_string = "heyhow$98765$you" works, 98765 , can parseint

.

my_string = "heyhow$$areyou" runtime error

.

string str = "heyhow$$areyou"; int startindex = str.indexof('$'); int lastindex = str.indexof('$', i+1); string nums = str.substring(startindex + 1, lastindex); int stringnumber = integer.parseint(nums); <--runtime error cause of no# parse 

thank in advance help. if have idea not involve using loop or conditional statement best!

use instead:

int stringnumber = nums.length() > 0 ? integer.parseint(nums) : 0; 

this parse number if length not zero, otherwise set stringnumber value 0. change if want different value empty string.

this still fail if string between delimiters not valid number. if possibility:

int stringnumber = 0; try {     stringnumber = integer.parseint(nums); } catch (numberformatexception nx)     // depends on how want handle invalid numbers }