I have a Boolean array and I am trying to make a corresponding char array, so that to each true in the new array corresponds a 1 and for each false a 0. this is my code but it seems the new array is empty, because nothing prints, the Boolean nums[] prints fine.
char[] digits = new char[n];
for (int i = 0; i < n; i++) {
if (nums[i]) {
digits[i] = 1;
}
else if (!nums[i]) {
digits[i] = 0;
}
}
for (int k = 0; k < n; k++) {
System.out.print (digits[k]);
}
Your problem is that you don't have quotes surrounding the 1 and 0.
for (int i = 0; i < n; i++) {
if (nums[i]) {
digits[i] = '1';
}
else {
digits[i] = '0';
}
}
Without the quotes, they are cast from ints to chars. 0 is actually the null character (NUL), and 1 is start of heading or something like that. Java chars are encoded using UTF-16 (they're 16 bits long). The characters '0' and '1' are actually encoded by 48 and 49 respectively (in decimal).
EDIT: Actually, don't look at the ASCII table, look at the Unicode character set. Unicode is really a superset of ASCII, but it'll probably be more useful than the ascii table
According to Primitive Data Types in the Language Basics lesson of trail Learning the Java Language in Oracle's Java tutorials:
The char data type is a single 16-bit Unicode character. It has a minimum value of '\u0000' (or 0) and a maximum value of '\uffff' (or 65,535 inclusive).
Unicode value 0 (zero) is a non-printing character, as is unicode value 1 (one). That's why you aren't seeing anything printed. Either change digits to a int array or fill it with character literals such as '0' or '1'
If you use int array, the following code will suffice:
int[] digits = new int[n];
for (int i=0; i<n; i++) {
if (nums[i]) {
digits[i] = 1;
}
}
for (int k=0; k<n; k++) {
System.out.print (digits[k]);
}
Note that a int array is implicitly initialized such that all the elements are initially 0 (zero).
you can do something like that
char[] myChars = new char[n/16];
for(int i=0;i<nums.length/16;i++);{
String myChar ="";
for(int j=0;j<16;j++){
if(nums[i*16+j])
myChar+="1";
else
myChar+="0";
}
myChars[i]=Integer.parseInt(myChar,2);
}
You can convert like this:
public static void main(String[] args) {
int n = 5;
boolean[] nums = { true, false, true, false, true };
char[] digits = new char[n];
for (int i = 0; i < n; i++) {
digits[i] = nums[i] ? '1' : '0';
}
}
nums[i] == true, just usenums[i], since that's a boolean itselfdigits[i]= nums[i] ? 1 : 0and completely dump your if else blocksn? Can you show us the contents ofdigits?