 Hi Guys, Welcome to Proto Coders Point.

In the Dart tutorial (Article), We will learn a basic program every beginner programmer should know, i.e. How to convert string character to ASCII value in dart programming language(code unit).

Introducation:

## What is ASCII value?

ASCII stands for “American Standart code for informaton exchange”. Is used for character encoding standard for electronic communication.

In simple words ASCII is a technique used to get ASCII number of a character.

Here is a ASCII value chart for you for reference.

Eg: Suppose you want ascii value of character capital ‘R’, you can check above ascii chart we have R = 82, like wise for small letter ‘r’ = 114.

### Ascii in dart – code unit in dart

In dart language, ascii is also know as code unit. In dart, each character is in UTF-16 form.

dart String class we have 2 methods to get code unit of a given character or also loop to string character to get all code units by each index of string value.

### Dart codeUnitAt(index) & codeUnits methods

As i said above, String class in dart has 2 main method that can be used to convert string to ASCII in dart.

1. string.codeUnitAt(index)

The codeUnitAt method is used to get ascii/code unit of character in string using it’s index value.

`int codeUnitAt(int index)`

It accepts a integer parameter (i.e. index) and return a integer value of ASCII code.

As you all know that index value starts from ‘0’. i.e. 0 index is the first character of a string, 1 is second character of a string and so on. Have a look to example.

`String name = "PROTO CODERS POINT";`

so if you want to convert index 0 position from string, then you can simple do it by:-

`name.codeUnitAt(0);  // here 0 is index value.`

1. Dart code for converting character to ascii value

```import 'dart:io';

void main() {

String ch = 'R';
print(' ASCII value of \${ch} is \${ch.codeUnitAt(0)}');

}```

output

2. Looping through all character in string.

```import 'dart:io';

void main() {

String name = 'PROTO CODERS POINT';

//loop to each character in string
for(int i = 0; i <name.length; i++){

print(' ASCII value of \${name[i]} is \${name.codeUnitAt(i)}');

}

}```

Output

2. string.codeUnits

The string.codeUnits is used to get all the ascii value / code units of a given string & it returns code unit(ascii value) in list.

defined as:

`List codeUnits`

To get list of code unit(ascii value) of a given string simply pass the string to this method.

`Eg: String name =''RAJAT";       print("ASCII list of given string  \${name.codeUnits}.`
```import 'dart:io';

void main() {

String name = 'PROTO CODERS POINT';

//returns list of code unit value.
print('Code Unit list: \${name.codeUnits}');

}```

output