问题描述
我一直试图找出我在打字稿中遇到的一个非常奇怪的问题.它将内联布尔表达式视为第一个值的类型，而不是完整的表达式.
I've been trying to figure out a very strange issue I ran into with typescript. It was treating an inline Boolean expression as whatever the first value's type was instead of the complete expression.
因此，如果您尝试以下简单操作:
So if you try something simple like the following:
var numericArray:Array<number> = [2,3,4,1,5,8,11];
var sorrtedArray:Array<number> = numericArray.sort((n1,n2)=> n1 > n2);
您将在 sort 方法中收到错误消息，指出参数与调用目标的任何签名都不匹配，因为您的结果是数字而不是布尔值.我想我遗漏了一些东西，因为我很确定 n1>n2 是一个布尔语句.
You will get an error on your sort method saying the parameters do not match any signature of the call target, because your result is numeric and not Boolean. I guess I'm missing something though cause I'm pretty sure n1>n2 is a Boolean statement.
推荐答案
错误完全正确.
正如它试图告诉你的那样，.sort() 接受一个返回数字而不是布尔值的函数.
As it's trying to tell you, .sort() takes a function that returns number, not boolean.
如果第一项较小，则需要返回负数；如果较大则为正，如果相等则为零.
You need to return negative if the first item is smaller; positive if it it's larger, or zero if they're equal.
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