V8中的函数调用优化

Question

Does V8 optimize multiple function calls that are the same function and arguments? In the example below Variance is called twice with the same arguments.

var Variance = require('variance');

function summary(items) {        
    return {
      variance: Variance(items.value.map((item) => item.value)),
      standardDeviation: Math.sqrt(Variance(items.value.map((item) => item.value))),
    };
}

Answer 1

v8确实优化了使用相同参数重复调用的函数，但是在您的示例中，它们实际上不是相同的参数（它们是不同的对象/数组引用）。