How To Easily Use Flutter For Loop Index

flutter for loop index

In this Flutter post, we will see how to get and use Flutter for loop index using a practical Flutter example. Everything about Flutter for loop index will be discussed in detail so you can have a clear idea of how to use it in your own Flutter apps as well.

What is Flutter For Loop Index?

Flutter for loop index is actually used to get the values from lists in Flutter apps. We will take values from list using the Flutter for loop index. Let’s start understanding it by using a proper Flutter example.

Implementing Flutter For Loop Index(Example)

In order to implement Flutter for loop index, first understand how Flutter for loop works.

Syntax

for(variable;condition;increment)
 {
     //do something
 }

See the below steps:

  • It starts with for keyword.
  • In parenthesis, first an integer variable in defined. Then condition is applied to that integer and finally an increment to the value of integer.
  • Body is defined as curly braces, anything write within these curly braces comes in the body of for loop.

Example

We will be using a list of items and fetch some specific value from that list using the Flutter for loop index. See below code:

List<dynamic> listOfValues=[
   'Circle',
   'Rectangle',
    34,
   'Green',
   'Car'
];

You can see that we have a list of dynamic type, means it can store any type of value. Let’s now use a Flutter for loop and search for the value of Green string.

We will first set the value of for loop to 0, the reason for that is the list items index start from 0. In the condition, we will use the list length and then increment that integer value by 1.

In the body section, we have used an if else statement. Reason is that the if statement will check if the current index is equal to the string Green then print that index value (list[integer]), if not then run the else block.

Let’s see practical code for this theory. See below code:

for(int i=0; i<listOfValues.length; i++)
{
    if(listOfValues[i]=='Green'){
       print(listOfValues[i]);
       break;
     }
     else{
       print('Green not found yet');
     }
}

Output:

Green not found yet
Green not found yet
Green not found yet
Green
First the value will be checked for the 0 index, means the first value. It will not match so the else block will be executed. Then in value 3(4th index), the value will be matched and the string Green will be printed. We have used break statement so when it runs, it will break the loop and come out of it.
You can see that there is one more value after green which is not checked, reason is that the break statement was executed before that which breaks the loop.
So this is how you can easily use Flutter for loop index. Hope you have gained a lot of knowledge from this post. Do ask questions related to the implementation of Flutter for loop index, if you still have any. I would be happy to answer.

Conclusion

To conclude, hope you now will easily use and customize Flutter for loop index in your own Flutter apps. I would be happy to receive your feedback on this post. Thank you for reading this Flutter post.

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