[Suggest a feature] Logical AND (&&) to execute code if it meets the condition

[titoworlddev]

I know that this operator (&&) already exists in dart but I would like it to have a use other than the ones it has.

It is common that sometimes we want to simply execute a small code only when a condition is met, for example:

String dart = 'awesome';
if (dart == 'awesome') {
  print('Dart is $dart');
}

Which is a bit long, but no problem, it can be shortened by putting it like this:

if (dart == 'awesome') print('Dart is $dart');

But when the condition gets a bit longer, the linter forces you to use the brackets because if you use clean code the execution after the condition would go on the line below. Which as I said, the linter forces you to put brackets.
For example:

String dart = 'awesome';
String dartVersion = '3.0.0';
String flutter = 'beautiful';
if (dart == 'awesome' && flutter == 'beautiful' && dartVersion == '3.0.0') {
  print('Dart $dartVersion and Flutter are very nice!');
}

This, if you want your code to not have unnecessary lines, can lead you to use ternaries and have codes like this:

dart == 'awesome' && flutter == 'beautiful' && dartVersion == '3.0.0'
      ? print('Dart $dartVersion and Flutter are very nice!')  : 0;

But of course, this can still be ugly because if we only need one execution, why put : 0;.

All this leads me to the use of the && operator as a solution to these cases. This could lead us to cleaner codes. For example, I am going to reduce the first code I put, and at the end I will use the && operator so that all the differences can be seen together.
Here the example:

String dart = 'awesome';
// Long way
if (dart == 'awesome') {
  print('Dart is $dart');
}

// Long way in 1 line
if (dart == 'awesome') print('Dart is $dart');

// reduced with ternary
dart == 'awesome' ? print('Dart is $dart') : 0;

// Clean code using the && operator
dart == 'awesome' && print('Dart is $dart');

I think this is much cleaner and easier to use for the cases that I have said. It would be nice to add it.

[mraleph]

The difference between

if (dart == 'awesome') print('Dart is $dart');

and

dart == 'awesome' && print('Dart is $dart');

Is really insignificant and the if one is much more clean and readable.

Also expression statements are already a thing - so requested syntax requires changing semantics of && when it is used in the expression statement, which introduces a very confusing discrepancy in the meaning (if (a && print()) is an error but a && print(); is okay).

So as such I would say that it's unlikely we are going add this. I let the language team have final say in this though.

[lrhn]

What @mraleph said.

Using if is only two characters longer, and much more readable.

The linter is optional. You can turn it off if you don't like it.
It requires braces for multi-line ifs for readability and safety.

The formatter also inserts newlines for readability, not to satisfy some foolish consistency.
You can ignore that, but you won't be able to auto-format then.

This, if you want your code to not have unnecessary lines, can lead you to use ternaries and have codes like this:

That saves one line, but at the cost of a total loss of readability.

If you care about the line length and readability, try introducing helper variables and methods:

var isAOk = dart == 'awesome' && flutter == 'beautiful' && dartVersion == '3.0.0';
if (isAOk) print('Dart $dartVersion and Flutter are very nice!');

Same number of lines, much more readable.

Brevity is about removing unnecessary noise, not reducing physical length. This feels, to me, like it's adding noise.
I'm not seeing a problem in need of a solution.

(Ob-pedantry: The ?/: operator is called, if anything, the conditional (expression) operator. It's not "the ternary operator", because Dart has two ternary operators. The word "ternary" means taking three operands, like "binary" means taking two.)

[titoworlddev]

What @mraleph said.

Using if is only two characters longer, and much more readable.

The linter is optional. You can turn it off if you don't like it. It requires braces for multi-line ifs for readability and safety.

The formatter also inserts newlines for readability, not to satisfy some foolish consistency. You can ignore that, but you won't be able to auto-format then.

This, if you want your code to not have unnecessary lines, can lead you to use ternaries and have codes like this:

That saves one line, but at the cost of a total loss of readability.

If you care about the line length and readability, try introducing helper variables and methods:

var isAOk = dart == 'awesome' && flutter == 'beautiful' && dartVersion == '3.0.0';
if (isAOk) print('Dart $dartVersion and Flutter are very nice!');

Same number of lines, much more readable.

Brevity is about removing unnecessary noise, not reducing physical length. This feels, to me, like it's adding noise. I'm not seeing a problem in need of a solution.

(Ob-pedantry: The ?/: operator is called, if anything, the conditional expression operator. It's not "the ternary operator", because Dart has two ternary operators. The word "ternary" means taking three operands, like "binary" means taking two.)

The conditional expression operator is a ternary operator.
You will tell me what it is, because it takes exactly three operands, 1- the condition, 2- the execution if that condition is fulfilled, 3- the execution if it is not fulfilled.
Any information you're looking for about a ternary operator will show you the "conditional expression operator".

And it's not just about saving space, or readability, it's also about comfort when writing a language.
I don't want to save lines or characters per se, but to make it more comfortable.

Here what is clear is the opinion of each person.

Perhaps or would have to corder && to do that, perhaps to make that if in a ternary operator or conditional logical operator (as you want to call it), you do not add : after the first default execution it works and do not have to add anything.
That is to say:

var dart = 'awesome';
dart == 'awesome' ? print('Dart is $dart!');
// Two are the same
if (dart == 'awesome') print('Dart is $dart!');

But I prefer && and have similarities with the other languages.
And also that this thing of each one does not have to change what is just adding it and thus gives the possibility that it is more versatile and that each one uses what they want.

Idk, do what you want.

[lrhn]

I'm sympathetic to the feeling. I'll code golf the heck out of my own code when I don't care about other people reading it.

It's just not something Dart, as a language, tries to optimize for. In that regard, Dart is opinioned. The style guide even more so than the language, but even the language tries to avoid having multiple ways to do the same thing.
Special-purpose shorthands for particular use-cases are fine, and we encourage you to use them when that use-case applies, but not two different, yet equally valid and powerful, ways to do just one thing.

Here that "guard + statement" feature is already taken by if statements.

There is no specific use-case where test && statement; would be more precise, expressive or significantly shorter than if (test) statement;. It's just a different, non-idiomatic way to write the same thing, one which looks exactly like a different language feature (short-circuiting logical and), and making different things look different is another design goal.

Saving one line of } is not enough to make it valuable. If that's what you want, just disable the "always use braces" lint, the language won't stop you. It's there because the style guide is more opinioned than the language, and if we added test && statement;, I'm sure the style guide would have an opinion on that too.

(I've considered something similar for expressions, test && generalExpression, multiple times, but it always comes back to Dart not being JavaScript, and static types just not matching up. I'd be more sympathetic to test ? expression with a default else-branch of null, but the grammar is not with us here. The ? and : characters are already used in so many ways that allowing a ?-condition without a : branch is going to be a foot-gun. I'd prefer if expressions for that, like #2306.)

[titoworlddev]

Actually if I have to give you the reason. It is not a significant saving of characters or lines.

I just wanted the language to have the versatility to adapt to all programmers and their preferences, but if it's not the goal of Dart or his development team then I'll accept it.

[munificent]

I'm going to close this because I think it's very unlikely we'd go in this direction. We want to please as many users as possible, but users have varying preferences and no one language can satisfy all of them.