JavaScript DataView.getInt32()用法及代碼示例

JavaScript DataView.getInt32() 是 dataView 中的內置方法。它用於在指定位置獲取有符號的 32 位整數(長)數。

注意：有符號整數值的 32 位整數值的範圍是從 2,147,483,648 到 2,147,483,647。

用法

dataview.getInt32(byteOffset)

參數

byteoffset: 從讀取數據的視圖開始的偏移量，以字節為單位。

返回值

此方法返回一個帶符號的 32 位整數。

瀏覽器支持

Chrome	9
Safari	5.1
Firefox	15
Opera	12.1

例子1

<script>
//JavaScript to illustrate dataview.getInt32() method
// creating a ArrayBuffer 
var JavaTpoint = new ArrayBuffer(8);
// creating a view
var arr = new DataView(JavaTpoint);
// put the value 23.3 at slot 1
document.write("If we give a float value, the output will be an Integer<br><br>");
arr.setInt32(1,23.3);
document.write(arr.getInt32(1));
//expected output:23
</script>

輸出：

If we give a float value, the output will be an Integer
23

例子2

<script>
//JavaScript to illustrate dataview.getInt32() method
// if there is no data to be stored then it returns Nan
// creating a ArrayBuffer 
var JavaTpoint = new ArrayBuffer(10);
// creating a view
var arr = new DataView(JavaTpoint);
// NO Data
arr.getInt32(1);
document.write("If there is no data to be stored, Output will Be:<br>")
document.write(arr.getInt32(1));
//expected output:0
</script>

輸出：

If there is no data to be stored, Output will Be:
0

例子3

<script>
//JavaScript to illustrate dataview.getInt32() method
// creating a ArrayBuffer 
var JavaTpoint = new ArrayBuffer(8);
// creating a view
var arr = new DataView(JavaTpoint);
//We can also use math function like Math.PI
document.write("Convert the PI value 3.14 to 3<br><br>");
arr.setInt32(1,Math.PI);
document.write(arr.getInt32(1));
//expected output:3
</script>

輸出：

Convert the PI value 3.14 to 3

3

示例 4

<script>
//JavaScript to illustrate dataview.getInt32() method
// creating a ArrayBuffer 
var JavaTpoint = new ArrayBuffer(8);
// creating a view
var arr = new DataView(JavaTpoint);
// put the value 7 at slot 1
arr.setInt32(1,7);
document.write("If we give an Integer value, Output will  be Integer<br><br>");
document.write(arr.getInt32(1));
//expected output:7
</script>

輸出：

If we give an Integer value, Output will be Integer

7

相關用法

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