What's the meaning of ? this sign in java?

Answer 1

▪The ?: operator in Java

The value of a variable often depends on whether a particular boolean expression is or is not true and on nothing else. For instance one common operation is setting the value of a variable to the maximum of two quantities. In Java you might write:

if( a > b ) {
max = a;
} else {
max = b;
}

Setting a single variable to one of two states based on a single condition is such a common use of 'if-else' that a shortcut has been devised for it, the conditional operator, ?: .

Using the conditional operator you can rewrite the above example in a single line like this:

max = ( a > b ) ? a : b;

( a > b ) ? a : b;  is an expression which returns one of two values, a or b.

The condition, ( a > b ), is tested.
• If it is 'true' the first value, a, is returned.
• If it is 'false' , the second value, b, is returned.

Whichever value is returned is dependent on the conditional test, a > b. The condition can be any expression which returns a boolean value.

Answer 2

Gysgaça if-else şertli operatorynyň gysgaldylan görnüşi. Köp programirleme dilinde gabat gelýär. Men JavaScript we PHP de gabat geldim.

Meselem:

if (a>b) {
// do something
} else {
// do something
}

// Ýokardaky meselemiň gysgaldylan görnüşi.
(a > b) ? a : b

Bu ýerde "?" - simwoly bolsa ":" - bu simwoly bolmasa diýip terjime edip alsaň düşnükli bolar, ýagny:
a > b-den uly bolsa ? birzatlar et bolmosa : başga zat et.

Answer 3

Thank you for explanation

Answer 4

Now I got it