вывести на консоль все unicode

for(int i =0; i< 128; i++){
    char c = (char)i;
    System.out.println(c);
}

Можно так. Просто int нужно явно приводить в char 2.8. char The final primitive data type to look at is char. Also called a character, char is a 16-bit integer representing a Unicode-encoded character. Its range is from 0 to 65,535. Which in Unicode represents ‘\u0000’ to ‘\uffff’. For a list of all possible Unicode values check out sites like Unicode Table. Let’s now declare a char: 1 2 3 4 5 char c = 'a'; char c = 65; char c; When defining our variables, we can use any character literal, and they will get automatically transformed into their Unicode encoding for us. A characters default value is ‘/u0000’.

Tnx

for(int i =0; i< 128; i++){
            char c = (char)i;
            System.out.println(c + " - " + i);
        }