Short form for Java if statement

Question

I know there is a way for writing a Java if statement in short form.

if (city.getName() != null) {
    name = city.getName();
} else {
    name=         


        

Answer 1

name = ( (city.getName() == null)? "N/A" : city.getName() );

firstly the condition (city.getName() == null) is checked. If yes, then "N/A" is assigned to name or simply name="N/A" or else the value from city.getName() is assigned to name, i.e. name=city.getName().

Things to look out here:

1. condition is in the parenthesis followed by a question mark. That's why I write (city.getName() == null)?. Here the question mark is right after the condition. Easy to see/read/guess even!
2. value left of colon (:) and value right of colon (a) value left of colon is assigned when condition is true, else the value right of colon is assigned to the variable.

here's a reference: http://www.cafeaulait.org/course/week2/43.html

Answer 2

in java 8:

name = Optional.ofNullable(city.getName()).orElse("N/A")

Answer 3

here is one line code

name = (city.getName() != null) ? city.getName() : "N/A";

here is example how it work, run below code in js file and understand the result. This ("Data" != null) is condition as we do in normal if() and "Data" is statement when this condition became true. this " : " act as else and "N/A" is statement for else condition. Hope this help you to understand the logic.

name = ("Data" != null) ? "Data" : "N/A";

console.log(name);

Answer 4

The way to do it is with ternary operator:

name = city.getName() == null ? city.getName() : "N/A"

However, I believe you have a typo in your code above, and you mean to say:

if (city.getName() != null) ...

Answer 5

1. You can remove brackets and line breaks.

if (city.getName() != null) name = city.getName(); else name = "N/A";

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2. You can use ?: operators in java.

Syntax:

Variable = Condition ? BlockTrue : BlockElse;

So in your code you can do like this:

name = city.getName() == null ? "N/A" : city.getName();

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3. Assign condition result for Boolean

boolean hasName = city.getName() != null;

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EXTRA: for curious

In some languages based in JAVA like Groovy, you can use this syntax:

name = city.getName() ?: "N/A";

The operator ?: assign the value returned from the variable which we are asking for. In this case, the value of city.getName() if it's not null.

Answer 6

I'm always forgeting how to use the ?: ternary operator. This supplemental answer is a quick reminder. It is shorthand for if-then-else.

myVariable = (testCondition) ? someValue : anotherValue;

where

• () holds the if
• ? means then
• : means else

It is the same as

if (testCondition) {
    myVariable = someValue;
} else {
    myVariable = anotherValue;
}