How to supply an Initial Value of the Text variable into a Text Widget Flutter

Question

Into the circleAvatar from flutter before user put they own image I want to replace the space with the Initial value the first digit of the currentUser variable name into TextWidget. it means for example the Name is "john" I want to get "J" how we can reach that?

  
  final imageUrl = true;

and build method

imageUrl ? CircleAvatar(
                radius: 60,
                backgroundImage: AssetImage(currentUser.imageUrl),)
                  : CircleAvatar(backgroundColor: Colors.yellow,
                child: Text(currentUser.name[0]),),
              SizedBox(
                height: 60,
              ),

In this way I get it but I dont know how to if imageUrl is null return currentUser.name[0]

I have edited the question I want to get the first digit of the text variable, if the name is John I want to get J — Tizi Dev
– Tizi Dev, Commented Nov 7, 2020 at 15:34

scrimau · Accepted Answer · 2020-11-07 22:03:58Z

1

to get the first character of a name:

final s = "John";
print(s[0]); // => J

to guard against null, you can use the ?? or the ? operator.

to get a circle avatar with a character text widget as child instead of an image, depending on whether imageUrl is null or not:

imageUrl ? CircleAvatar(backgroundImage: NetworkImage(imageUrl),)
 : CircleAvatar(backgroundColor: Colors.brown.shade800,
    child: Text(currentUser && currentUser.isNotEmpty? currentUser[0] : "default"),)

edited Nov 7, 2020 at 22:03

answered Nov 7, 2020 at 15:30

scrimau

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4 Comments

Tizi Dev Over a year ago

I meant initialValue of the Text Variable for example the first digit on the name.

scrimau Over a year ago

to get the first character of a string variable s just use s[0], provided you know s is not empty

Tizi Dev Over a year ago

i added: bool imageUrl = false; final s = "${currentUser.name}"; and the code: imageUrl ? CircleAvatar( radius: 60, backgroundImage: AssetImage(currentUser.imageUrl),) : CircleAvatar(backgroundColor: Colors.yellow, child: Text( currentUser.name.isEmpty && currentUser.name.isNotEmpty? s[0] : "default"),), Image on circeavatar showing corrently but if I remove image the Initial value of the variable currentUser.name is not showing. I added the code above

scrimau Over a year ago

imageUrl does not need to be a bool. a String (url) will also do. when imageUrl is null, it will be treated like false would. Your edited question is still confusing though. You can either use the code in a method returning a String or in a method returning a Widget (a build method f.e.). A method returning once a Widget and once a String is not rly helpful. In either case, you might wanna use if and else instead of ? and :, if this is confusing for you.

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