Javascript implements finding the area of ​​a circle with a given radius_javascript skills

The code is quite simple, so I won’t go into too much nonsense here. Friends, please refer to it for yourselves.

<script>
var circularityArea = new Function("r","return r*r*Math.PI"); //创建一个函数对象
var rCircle = 2;//给定圆的半径
var area = circularityArea(rCircle);
alert("半径为2的圆面积为：" + area);
</script>

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