How to Use Flutter If Not boolean Value in 2023

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The most common conditional statement is used flutter if not boolean value. This is very commonly used in different logical functions. In this article, we will discuss logical operators and flutter if not boolean value. bool is the type of Dart that represents a boolean value that can be true or false.

Flutter If Not boolean Value

The logical operator is the same in all languages. In dart, there is no difference. The logical operator also uses to combine or invert the boolean expressions.

&&Logical AND
||Logical OR
!exprinvert boolean

Example 1:

bool isDownloading = true;
bool isConnection = false;

assert(!isDownloading ); // true
assert(isConnection || isDownloading ); // true because at least one is true
assert(isDownloading && !isConnection); // true because both are true

Example 2:

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Let’s consider, we will download a new mp3 from the URL. The important books is isDownloadReady. When it was true, then app start downloading, if not then it will not download the mp3. There have a gallery so I use a bool ifStorageFull, so if it is true then will appear a message that the storage is full, delete some mp3. Let’s consider that the gallery exists 50 mp3.

bool ifStorageFull;
int mp3;
Widget build(BuildContext context) {
  if (mp3> 100) {
    ifStorageFull= true;
  } else {isStorageFull = false;}
return Container(
  child: ifStorageFull? Text("Delete some images") : Text("You can  add more pictures")

So the schema is:

if (fullfilled condition) {
   yourBool = true;
} else {yourBool} = false;

Example 3:

// first assign

bool isFileExist = true;
bool isInternetConnection = true;

// we can combine boolean with  &&, ||, and other symbols
// if isFileExist is true AND isInternetConnection is true
bool isDownloadAnotherFile = isFileExist && isInternetConnection;

if (isDownloadAnotherFile ) {
  print("Downloading next file!");
} else {
  print("Downloading current File!");

At last of Flutter If Not boolean Value

  • Declare the bool with the name isAnyThing or isSomething. example: isDownloading, isFileExist.
  • Variable true or false check.
  • Execute the code after resulting in the true or false.

Read More:

Top 3 Best Ways to Use Flutter Conditional Show Widget

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Md Nazmul Islam
Md Nazmul Islam
Flutter Developer | Technical Writer | App Store Optimizer - I have been developing mobile apps and libraries using Google’s Flutter framework since its inception. I have also skilled in the native android platform. I love to solve problems and share knowledge from my technical writing skill. I have experience in App store optimization.

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