java - Getting ArrayList.get() to return -

java - Getting ArrayList.get() to return -

i trying write a simple function translating integer, , vice versa, 3bit binary string 0 padding. test inttobinary method created simple loop adding integers 1 5 , translating each number binary string, combine binary strings larger string.

arraylist citylist = new arraylist(); string gene = ""; for(int = 1; i<5;i++){ citylist.add(i, i); gene += inttobinary(i); system.out.println(gene + "" + citylist.get(i)); } system.out.println(gene);

when tried running little bit of code error @ citylist.get(i) shouldn't object.get(i) method returns variable @ index i? tried initializing int doing int citynum = (int)citylist.get(i) got error saying object found instead of int.

the variable type used in object.add(int index, object) int method should homecoming int variable.

if understand question, like

for (int = 0; < math.pow(2, 3); i++) { stringbuilder sb = new stringbuilder(integer.tobinarystring(i)); while (sb.length() < 3) { sb.insert(0, '0'); } system.out.printf("%d = %s%n", i, sb.tostring()); }

output is

0 = 000 1 = 001 2 = 010 3 = 011 4 = 100 5 = 101 6 = 110 7 = 111

to go vice-versa can utilize integer.parseint(string,int) like

int val = integer.parseint("001", 2); // <-- 1

java