post increment operator java

by

Let’s break down your own argument:

According to the author,

j=j++;

is similar to

temp=j;
j=j+1;    // increment
j=temp;   // then assign

Yes, you’re right so far…, but here’s where you got it wrong:

But

a=b++;

makes b=1. So it should’ve evaluated like this,

a=b;      // assign
b=b+1;    // then increment

WRONG! You’re not applying the rule consistently! You’ve changed the order from increment then assign to assign then increment!!! It’s actually evaluated like this:

temp=b;
b=b+1;     // increment
a=temp;    // then assign

Basically assignments of this form:

lhs = rhs++;

is similar to doing something like this:

temp = rhs;
rhs = rhs+1;  // increment
lhs = temp;   // then assign

Apply this to a = b++;. Then apply it also to j = j++;. That’s why you get the results that you get.

What you did was you came up with your own interpretation of what a = b++; does — a WRONG interpretation that doesn’t follow the above rule. That’s the source of your confusion.

See also

  • JLS 15.14.2 Postfix Increment Operator

    “…the value 1 is added to the value of the variable and the sum is stored back into the variable […] The value of the postfix increment expression is the value of the variable before the new value is stored.”

More Related Contents:

  1. Why does variable i not change after i=i++?
  2. How to construct a loop that produces a temp conversion chart
  3. How do the post increment (i++) and pre increment (++i) operators work in Java?
  4. What is x after “x = x++”?
  5. Java: Prefix/postfix of increment/decrement operators?
  6. What is more efficient, i++ or ++i? [duplicate]
  7. Incrementor logic
  8. Java increment and assignment operator [duplicate]
  9. Post increment operator not incrementing in for loop [duplicate]
  10. Why doesn’t changing the pre to the post increment at the iteration part of a for loop make a difference?
  11. Is ++x more efficient than x++ in Java?
  12. Why does post-increment work on wrapper classes
  13. to output all elements of square matrix in a spiral
  14. How to read XML using XPath in Java
  15. How to see JIT-compiled code in JVM?
  16. Java how to replace 2 or more spaces with single space in string and delete leading and trailing spaces
  17. Java error: Only a type can be imported. XYZ resolves to a package
  18. Fuzzy string search library in Java [closed]
  19. What are the pros and cons of performing calculations in sql vs. in your application
  20. How to resize text in java
  21. Annotations from javax.validation.constraints not working
  22. Write HTML file using Java
  23. Java rounding up to an int using Math.ceil
  24. Firebase can’t save retrieved data to ArrayList
  25. Merging Two JSON Documents Using Jackson
  26. What is .intValue() in Java?
  27. Mapping JPA or Hibernate projection query to DTO (Data Transfer Object)
  28. Why does array indexing in Java start with 0?
  29. How can you escape the @ character in javadoc?
  30. Java Enum getDeclaringClass vs getClass

Leave a Comment