I++, i--.... And all the equivalents

Question

An explanation please?

I can't remember what they mean.

Answer 1

• Increment and Decrement Operators

Like C and C++, Java provides increment and decrement operators. Specifically, it provides the plus-one increment (++) and decrement (−−) operators.

 • If such an operator is used in front of a variable reference, then 1 is added to (or subtracted from) the variable and its value is read into the expression.

 • If it is used after a variable reference, then the value is first read and then the variable is incremented or decremented by 1.

So, for example, the code fragment

    int i = 8;
    int j = i++;
    int k = ++i;
    int m = i−−;
    int n = 9 + i++;

assigns 8 to j, 10 to k, 10 to m, 18 to n, and leaves i with value 10.

 ➝ Remember to use  🔍SEARCH. . .  bar to avoid from posting duplicate threads!

Answer 2

BrandnameOra

  [ ++i and i++ both add 1 to i ]

However, ++i returns the new value, and
i++ returns the old value.
Likewise for decrement, --i and i--, which subtracts 1.

• https://code.sololearn.com/chPAcDs7YZgV/?ref=app

Answer 3

BrandnameOra
😊Here is a great example with great explanation!👍

• https://code.sololearn.com/cKldmmXb8l8R/?ref=app

Answer 4

Try printing the values directly to console you will understand it straight away. Example

//using 2 seperate variables x and y
int x = 0;
int y = 0;

//Here we use the value of x first then increment afterwards
System.out.print(x++); //output 0

//Here we increment the value of y first and then use it
System.out.print(++y); //output 1

Answer 5

Using ++ is useful when you want to use a variable value and increment it by 1 same time. ++x if you want to increment x before using it. x++ if you want to use the original value of x before incrementing it.

Answer 6

> I can't remember what they mean.

Just read the expression from the left to the right: in i++, i is used first and then incremented. In --i, i is first decremented and then its (new) value is used.

Answer 7

i++ is the same as incrementing i by 1 or i = i + 1

similarly i-- is the same as decrementing i by 1 or i = i-1

to increment or decrement by more than one you could use i+=2 or i-=2 respectively

Answer 8

Thank you all very much for your answers.
I'm getting the hang of it now and it's good stuff to have gotten.

Thank you again