JavaScript DataView setInt8() Method

The JavaScript DataViewsetInt8()method is used to store an8-bit signedinteger value in the byte (1 byte = 8-bit) at the start of the specified byteOffset of this DataView.

This method throws a'RangeError'if the byteOffset parameter value is outside the bounds of this DataView.

Syntax

Following is the syntax of the JavaScript DataView setInt8() method −

setInt8(byteOffset, value)

Parameters

This method accepts two parameters named 'byteOffset' and 'value', which are described below −

• byteOffset − The position in the DataView where the byte will be stored.
• value − A signed 8-bit integer that needs to be stored.

Return value

This method returns 'undefined'.

Example 1

The following program demonstrates the usage of the JavaScript DataView setInt8() method.

<html>
<body>
<script>
   const buffer = new ArrayBuffer(8);
   const data_view = new DataView(buffer);
   const byteOffset = 1;
   const value = 45;
   document.write("The byteOffset: ", byteOffset);
   document.write("<br>The data value: ", value);
   //using the setInt8() method
   document.write("<br>The setInt8() method returns: ", data_view.setInt8(byteOffset, value));
</script>
</body>
</html>

Output

The above program returns 'undefined' −

The byteOffset: 1
The data value: 45
The setInt8() method returns: undefined

Example 2

In the following example, we use the setInt8() method to store the 8-bit signed integer43234in the byte at the specified byteOffset0in this DataView.

<html>
<body>
<script>
   const buffer = new ArrayBuffer(8);
   const data_view = new DataView(buffer);
   const byteOffset = 1;
   const value = 20;
   document.write("The byteOffset: ", byteOffset);
   document.write("<br>The data value: ", value);
   //using the setInt8() method
   document.write("<br>The setInt8() method returns: ", data_view.setInt8(byteOffset, value));
   document.write("<br>The stored value: ", data_view.getInt8(byteOffset));
</script>
</body>
</html>

Output

Once the above program is executed, it will store the given value 20 in bytes of this DataView −

The byteOffset: 1
The data value: 20
The setInt8() method returns: undefined
The stored value: 20

Example 3

If the value of thebyteOffsetparameter isoutsidethe bounds of this DataView, it will throw a'RangeError'exception.

<html>
<body>
<script>
   const buffer = new ArrayBuffer(8);
   const data_view = new DataView(buffer);
   const byteOffset = -1;
   const value = 10;
   document.write("The byteOffset: ", byteOffset);
   document.write("<br>The data value: ", value);
   try {
      //using the setInt8() method
      data_view.setInt8(byteOffset, value);
   } catch (error) {
      document.write("<br>", error);
   }
</script>
</body>
</html>

Output

After executing the above program, it will throw a 'RangeError' exception.

The byteOffset: -1
The data value: 10
RangeError: Offset is outside the bounds of the DataView