Is there a difference between x++ and ++x in java?

Question

Is there a difference between ++x and x++ in java?

Solution 1

++x is called preincrement while x++ is called postincrement.

int x = 5, y = 5;

System.out.println(++x); // outputs 6
System.out.println(x); // outputs 6

System.out.println(y++); // outputs 5
System.out.println(y); // outputs 6

Solution 2

yes

++x increments the value of x and then returns x
x++ returns the value of x and then increments

example:

x=0;
a=++x;
b=x++;

after the code is run both a and b will be 1 but x will be 2.

Solution 3

These are known as postfix and prefix operators. Both will add 1 to the variable but there is a difference in the result of the statement.

int x = 0;
int y = 0;
y = ++x;            // result: y=1, x=1

int x = 0;
int y = 0;
y = x++;            // result: y=0, x=1

Solution 4

Yes,

int x=5;
System.out.println(++x);

will print 6 and

int x=5;
System.out.println(x++);

will print 5.

Solution 5

In Java there is a difference between x++ and ++x

++x is a prefix form: It increments the variables expression then uses the new value in the expression.

For example if used in code:

int x = 3;

int y = ++x;
//Using ++x in the above is a two step operation.
//The first operation is to increment x, so x = 1 + 3 = 4
//The second operation is y = x so y = 4

System.out.println(y); //It will print out '4'
System.out.println(x); //It will print out '4'

x++ is a postfix form: The variables value is first used in the expression and then it is incremented after the operation.

For example if used in code:

int x = 3;

int y = x++;
//Using x++ in the above is a two step operation.
//The first operation is y = x so y = 3
//The second operation is to increment x, so x = 1 + 3 = 4

System.out.println(y); //It will print out '3'
System.out.println(x); //It will print out '4' 

Hope this is clear. Running and playing with the above code should help your understanding.

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Comments

[Alberto de Paola]

This "answer" just tells you a test case output, and I consider that outputs are not answers. On the contrary, normally the (unexpected) result of some code execution leads as to the question. Hence my down vote.

[Thom]

This response would be even better if accompanied by a few words of explanation.

[hyper-neutrino]

Shouldn't it be suffix?