javascript - 函数中可变数量的参数

是否可以根据传递的参数数量告诉函数应为其参数赋予什么名称？像这样：

function soSwag(swagLevel, swagStart, swagDuration || swagStart, swagStop){}

最佳答案

一些支持可变类型参数的流行库（例如jQuery）所做的是，它们检查参数，然后相应地交换值：

function soSwag(swagLevel, swagStart, swagDuration) {
    if (arguments.length === 2) {
        var swagStop = swagStart;   // 2nd arg becomes swagStop
        swagStart = swagLevel;      // first arg becomes swagStart

        // code here that uses swagStart and swagStop
        // as called like soSwag(swagStart, swagStop)

    } else {

        // code here that uses swagLevel, swagStart, swagDuration
        // as called like soSwag(swagLevel, swagStart, swagDuration)

    }
}