Convert boolean to int in Java
What is the most accepted way to convert a boolean
to an 开发者_高级运维int
in Java?
int myInt = myBoolean ? 1 : 0;
^^
PS : true = 1 and false = 0
int val = b? 1 : 0;
Using the ternary operator is the most simple, most efficient, and most readable way to do what you want. I encourage you to use this solution.
However, I can't resist to propose an alternative, contrived, inefficient, unreadable solution.
int boolToInt(Boolean b) {
return b.compareTo(false);
}
Hey, people like to vote for such cool answers !
Edit
By the way, I often saw conversions from a boolean to an int for the sole purpose of doing a comparison of the two values (generally, in implementations of compareTo
method). Boolean#compareTo
is the way to go in those specific cases.
Edit 2
Java 7 introduced a new utility function that works with primitive types directly, Boolean#compare
(Thanks shmosel)
int boolToInt(boolean b) {
return Boolean.compare(b, false);
}
boolean b = ....;
int i = -("false".indexOf("" + b));
import org.apache.commons.lang3.BooleanUtils;
boolean x = true;
int y= BooleanUtils.toInteger(x);
public int boolToInt(boolean b) {
return b ? 1 : 0;
}
simple
If you use Apache Commons Lang (which I think a lot of projects use it), you can just use it like this:
int myInt = BooleanUtils.toInteger(boolean_expression);
toInteger
method returns 1 if boolean_expression
is true, 0 otherwise
That depends on the situation. Often the most simple approach is the best because it is easy to understand:
if (something) {
otherThing = 1;
} else {
otherThing = 0;
}
or
int otherThing = something ? 1 : 0;
But sometimes it useful to use an Enum instead of a boolean flag. Let imagine there are synchronous and asynchronous processes:
Process process = Process.SYNCHRONOUS;
System.out.println(process.getCode());
In Java, enum can have additional attributes and methods:
public enum Process {
SYNCHRONOUS (0),
ASYNCHRONOUS (1);
private int code;
private Process (int code) {
this.code = code;
}
public int getCode() {
return code;
}
}
If true -> 1
and false -> 0
mapping is what you want, you can do:
boolean b = true;
int i = b ? 1 : 0; // assigns 1 to i.
If you want to obfuscate, use this:
System.out.println( 1 & Boolean.hashCode( true ) >> 1 ); // 1
System.out.println( 1 & Boolean.hashCode( false ) >> 1 ); // 0
Lets play trick with Boolean.compare(boolean, boolean)
. Default behavior of function: if both values are equal than it returns 0
otherwise -1
.
public int valueOf(Boolean flag) {
return Boolean.compare(flag, Boolean.TRUE) + 1;
}
Explanation: As we know default return of Boolean.compare is -1 in case of mis-match so +1 make return value to 0 for False
and 1 for True
public static int convBool(boolean b)
{
int convBool = 0;
if(b) convBool = 1;
return convBool;
}
Then use :
convBool(aBool);
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