JS中布尔运算符的优先顺序是什么? [英] What is the order of precedence for boolean operators in JS?

问题描述

 e.pageX = e.clientX + (html && html.scrollLeft || body && body.scrollLeft || 0) - (html.clientLeft || 0)

该表达式如何计算?

推荐答案

您可以在MDN上找到Javascript运算符的优先级表:

You can find a precedence table for Javascript operators on MDN: https://developer.mozilla.org/en/JavaScript/Reference/Operators/Operator_Precedence. It is a great source for Javascript documentation in general.

无论如何，& 的优先级高于 || ，因此 a&&b ||c ||d 等效于((((a&& b)|| c)|| d).这与许多其他具有C风格语法的语言相似.

Anyway, && has higher precedence than || so a && b || c || d is equivalent to (((a && b) || c) || d). This is similar to many other language with a C-inspired syntax.

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