两个知识点: Operators/Operator_Precedence Operators/Conditional_Operator 简而言之 + 的优先级 大于 ? 所以原题等价于 'Value is true' ? 'Somthing' : 'Nonthing' 而不是 'Value is' + (true ? 'Something' : 'Nonthing') 答案'Something' 第5题 var name = 'World!'; (function () { if (typ...
When operators have the same precedence (like + and -), they are computed from left to right: letx =100/50*3; Try it Yourself » Operator Precedence Values Expressions in parentheses are computedbeforethe rest of the expression Function are executedbeforethe result is used in the rest of...
JavaScript has21levels of operator precedence. You can check them outhere. The table shows the operator, the usage of the symbol, which direction we should read the operation and the precedence fromhighest (21)to thelowest (1)precedence. Imagine an operation like the following: (3 + 10) *...
The + operator, and the += operator can also be used to concatenate (add) strings.Given that t1 = "Good ", t2 = "Morning", and t3 = "", the table below explains the operators:OperExamplet1t2t3Try it + t3 = t1 + t2 "Good " "Morning" "Good Morning" Try it » += t1 +=...
Table Operator precedence determines the order in which operators are evaluated. Operators with higher precedence are evaluated first. A common example: 3 + 4 * 5 // returns 23 The multiplication operator ("*") has higher precedence than the addition operator ("+") and thus will be evalua...
The precedence rules are listed in this table:OperatorDescription - + ++ -- unary operators, increment and decrement * / % multiply/divide + - addition/subtraction = += -= *= /= %= **= assignmentsOperations on the same level (like + and -) are executed in the order they are found...
运算符优先级别(Operator Precedence)高的先执行 圆括号()用来提高运算的优先级(它的优先级最高),即圆括号中的表达式会第一个运算圆括号不是运算符,而是一种语法结构。它一共有两种用法:一种是把表达式放在圆括号之中,提升运算的优先级;另一种是跟在函数的后面,作用是调用函数。
https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/Operator_Precedence#table。 第15题 "use strict" a = 1 var a = 2 console.log(window.a) console.log(a) 1. 2. 3. 4. 5. 答案 2、2 解析 var声明会把变量提升到当前作用域顶部,所以a=1并不会报错,另外在全局作用...
4从左到右… || … 空值合并 (??)从左到右… ?? … 3条件(三元)运算符从右到左… ? … : … 2赋值从右到左… = … … += … … -= … … **= … … *= … … /= … … %= … … <<= … … >>= … … >>>= … ...
运算符优先级式语法分析器(operator precedence parser) deferred parser / diet parser(延迟语法分析) 从中间表示到目标代码的编译器(IR-to-target-code compiler) 也叫做编译器的“后端”。但因为这部分编译器经常被叫做“JIT”编译器,所以单独拿出来写