How to use a Ternary Operator with multiple condition in flutter dart?

If you're referring to else if statements in dart, then this ternary operator:

(foo==1)? something1():(foo==2)? something2(): something3();

is equivalent to this:

if(foo == 1){
    something1();
}
elseif(foo == 2){
    something2();
}
else something3();

For three conditions use:

value: (i == 1) ? 1 : (i == 2) ? 2 : 0

Try below

(2 > 3)?print("It is more than 3"):print("It is less than 3");
////Prints It is less than 3 to the console

Try this:

foo == 1 ? doSomething1 : (foo == 2 ? doSomething1 : doSomething2)

If you have to include multiple conditions then you should use parantheses

it is easy,

if(foo == 1 || foo == 2)
 {
  do something
  }
 {
  else do something
  } 

it can be written thus for OR statement

foo==1 || foo==2 ? do something : else do something

it can be written thus for AND statement

foo==1 && foo==2 ? do something : else do something

both will work perfectly

EDITED

The original answer has run a little bit of from the question asked. Below is my edited answer.

To use ternary operator

(foo == 1 || foo == 2) ? doSomething() : doSomethingElse();

For my cleaner approach

{1, 2}.contains(foo) ? doSomething() : doSomethingElse();

ORIGINAL

The cleaner way for me is

if ({1, 2}.contains(foo)) {
  //do something
} else {
  //do something else
}

For AND try this, // here both or multiple conditions needs to satisfy

if (primaryImageUploaded == true && signatureImageUploaded == true) {
    // status bool condition in true 
    } else {
     // if false 
    }

For OR try this, // here need ONLY any one condition to satisfy

if (primaryImageUploaded == true || signatureImageUploaded == true) {
    // status bool condition in true 
    } else {
     // if false 
    }

Another Dart Syntax

if (100 > 50) {
  print("100 is greater than 50");
 }

Here is an example of the same

Text((managerStatus == "pending")
    ? "Requested"
        : (adminStatus == "confirm")
    ? "Amount credited"
        : "Admin Pending")

Simple Multiple check in one condition

if(in_array($foo, [1,2,'other'])) {
    //do something
}
else {
    //else do something
}