JavaScript atan2() method


JavaScript atan2() Method

Instance

Instance

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>

<p id="demo">单击按钮显示坐标（4,8）与X轴的角度的弧度</p>
<button onclick="myFunction()">点我</button>
<script>
function myFunction(){
	document.getElementById("demo").innerHTML=Math.atan2(8,4);
}
</script>

</body>
</html>

Run Example»

Click the "Run Example" button to view the online example

Definition and usage

atan() method can return the arctangent value of a number .

The returned value represents the angle in radians between the coordinates (x, y) and the X-axis.

Note: atan2() has two parameters, the y coordinate is passed as the first parameter, and the X coordinate is passed as the second parameter.

Browser support

QQ截图20161108165429.png

All major browsers support the atan2() method

Syntax

Math.atan2(y,x)

##ParametersDescriptionRequired. A number representing the Y coordinate is required. A number representing the x coordinate
y
x
Return value

TypeDescription#NumberTechnical Details
## The arctangent of
x. The returned value is a value in radians between -PI/2 and PI/2.

JavaScript Version:
1.0


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