Dart Conditional Expressions: Ternary Operator of Java. Dart Flutter Tutorial #4.2

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In this beginner tutorial, explore conditional expressions which is similar to what we have as ternary operator in Java. Also explore second type of expression such as "expression1 ?? expression2".
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[@Nypro6]

4:50
Maybe this would also be a great solution:
print("${a < b ? a : b} is smaller");

[@justarandomfishguy8868]

You might like me got an error on trying to let the String variable stay null, I found out that after flutter 2.0 which brought in Null safety feature, you need to specify the variable is nullable as follow:
_String ? name = null_

[@faheemsameer1598]

thank you, faced the issue and your answer came out first

[@emmanuelmushi3072]

Thank you very much.

[@smoke_ffx.]

Thanks

[@saisasisai]

Nice 👌 Tutorial series ...!

[@mohanbarman5982]

really thanks for your tutorials ;-)

[@mohanbarman5982]

print("${a>b ? b : a} is smaller than ${a

[@krishnakumarramachandran5888]

Good Explanation sir👌

[@smartherd]

thanks

[@dineshbhavsar1435]

Sir It Show Me Error: A value of type 'Null' can't be assigned to a variable of type 'String'.

[@afaqueali9706]

Yes, because this video is old and now dart has included null safety in its latest version. Try using 'var' instead of 'String' you will see no error .

[@NusratJahan-pg1mi]

@@afaqueali9706 nice it's work . take love

[@emmanuelmushi3072]

You can try this also: String ? name = null
It worked for me.

[@LolLol-br6zj]

to wite the null value in variable use the syntax
String? "Variable name" = null;
if you have any confusion please find the example below
void main() {
//String name = "Ak";
String? name = null; // Use nullable type String?
String theName = name ?? "PK";
print(theName); // This will print "PK" because name is null
}

[@thebongtwister]

At 5.38, why you not using " start and close inside print ?

[@karthickrajalearn]

In 4m 49 sec
It is Very useful

[@faisalfotoh1909]

unlocked: i

[@SyedAlirazarizvi72]

Hi,
I am trying to type syntax same as you for testing the second method of conditional expressions exp1 ?? exp2.
String name = "Allan";
String nameToPrint = name ?? "Guest User";
print(nameToPrint);
On the first expression name the program is showing an error "Condition must have a static type of 'bool'
In the output window the error pointer is pointing on second question mark, also the red mark is pointing on second question mark in the code.
Can you please help me finding out the actual error?
Thanks for presenting such a helpful series of videos.

[@renziz9541]

that's weird, I just tested your code and it worked fine for me. are you using the DartPad compiler?

[@afaqueali9706]

Yes, because this video is old and now dart has included null safety in its latest version. Try using 'var' instead of 'String' you will see no error .
try this code.
var name = null;
String nameToPrint = name ?? "Guest User";
print(nameToPrint);

[@AbhayKumar-lf3ct]

@@afaqueali9706 but how to print name as "tom"

[@chiragbansal5060]

Please tell me how to take input from the user.

[@ritikmitra7802]

it is a big procedure but you can take input from user by using if and readsync some code is not working because now the latest version is DART 2 and he is explaining dart 1 thats why

[@bscoeryan]

Can have the first video if else..

[@imgeekyt]

String name=null;
got error on above line
The value 'null' can't be assigned to a variable of type 'String' because 'String' is not nullable.

[@LolLol-br6zj]

to wite the null value in variable use the syntax
String? "Variable name" = null;
if you have any confusion please find the example below
void main() {
//String name = "Ak";
String? name = null; // Use nullable type String?
String theName = name ?? "PK";
print(theName); // This will print "PK" because name is null
}

[@ritikmitra7802]

String name = null; is not working ! but String? name = null; is working explain ?

[@emmanuelmushi3072]

Instead of using String name=null, use this code:
String ? name = null;
You can also use:
var name = null;

[@wajdibac3236]

now you can't assign String name = null .. It should be String? name = null; or it will not work .

[@corasfm45]

and how to name it tio? it still give warning operand in line code String nameToPrint = name ?? "Guest User" has type String which excluded null

[@wajdibac3236]

@@corasfm45 this code works fine in visual code :
void main() {
// Conditional Expressions
// 1. condition ? exp1 : exp2
// If condition is true, evaluates expr1 (and returns its value);
// otherwise, evaluates and returns the value of expr2.
int a = 5;
int b = 7;
if (a < b) {
print('$a is smaller');
} else {
print('$b is smaller');
}
//we can do it instead like this
a < b ? print('$a is smaller') : print('$b is smaller');
// or like this
int smallerNumber = a < b ? a : b;
print('$smallerNumber is smaller ');
// 2. exp1 ?? exp2
// If expr1 is non-null, returns its value; otherwise, evaluates and
// returns the value of expr2.
String? name = null;
String nameToPrint = name ?? "Guest User";
print(nameToPrint);
}

[@corasfm45]

@@wajdibac3236 i use visual code too and dart extension latest v3.56.0. i mean if i want the output like name = tio. example code
String? name = null;
name = "Tio";
String nameToPrint = name ?? "Guest User";
print(nameToPrint);
it give me error warning like my previous question but the output is right it print Tio. and is there a way to get rid that warning error?

[@wajdibac3236]

@@corasfm45 Sorry I just read the error in your comment. that's related to dart version don't worry about it. It is not an error, if you check below that error you will find that your code is actually get executed successfully and you can see the result ...

[@sanskaarz]

@@wajdibac3236 👍

[@worldofrup9085]

This is ternary operator

[@rockstreethomie]

String is not nullable

[@nikhiljohnjose6739]

Yup. Try using String? instead of String
String? name = null should work.

[@rockstreethomie]

@@nikhiljohnjose6739 It worked.Thanks Nikhil Bro

[@snehagsneha4542]

video not clearly visible

[@adii18s]

your download quality is low make it high in settings