数组转字符串:
int a[] = new int[]{1,2,3,4,5};
String b = "";
for(int i:a){
b=b+i;
}
System.out.println(b);//12345
数组转ArrayList
int a[] = new int[]{1,2,3,4,5};
List<Integer> ls = Arrays.stream(a).boxed().collect(Collectors.toList());
ArrayList<Integer> arr = new ArrayList<>();
arr.addAll(ls);
System.out.println(arr);
字符串转数组
String s = "12345";
int a[] = new int[s.length()];
for(int i =0;i<s.length();i++){
a[i] = (int)(s.charAt(i)-'0');
}
System.out.println(a[1]);//2
字符串转ArrayList
String s = "12345";
ArrayList<Integer> arr = new ArrayList<>();
for(int i =0;i<s.length();i++){
char c = s.charAt(i);
arr.add((int)c-'0');
}
System.out.println(arr);//[1, 2, 3, 4, 5]
ArrayList转数组