块语句又叫复合语句,javascript将多条语句联合在一起,形成一条复合语句(compound statement) 复合语句只须用花括号将多条语句括起来即可 { x = Math.PI; cx = Math.cos(x); console.log(cx); } 关于块语句,有以下几点注意事项: 【1】语句块的结尾不需要分号。块中的原始语句必须以分号结束,但语句块不需要...
1if (expression) {2statement3} 这种形式中,需要计算 expression 的值,如果结果是真值,那么就执行 statement 为了避免歧义,建议总是给 if 语句添加花括号 else if 1if (expression) {2statement3} else if (expression) {4statement5} switch 1switch(expression) {2statement3} 循环 while 1var count = 0;...
But && is not the only operator you could use to set up the compound statement. Let us assume that instead of requiring that our boy has done his homework AND that he got an “A” grade, that he needs an “A” OR if his homework is done then he can go play. In this case we ...
Functions that contain atry-finallystatement Functions that contain acompound let assignment Functions ...
function Identifier ( ParameterListOpt ) CompoundStatement Statement 它的开头是用缩进来表示的,就是相当于产生式左边的非终结符,非终结符之后跟着一个冒号,之后给了两个空格的缩进。然后在 JavaScript 的标准中,它的非终结符,加号、减号是用加粗的黑字体来表示终结符的。
首先对exp做判断,是否是 member expression、是否是 inline statement,是否有多个 statement。然后出现了exp的改写,根据判断生成了 compound expression,实际就是转换成了函数表达。看来isMemberExp、isInlineStatement这两个判断影响了最终codegenNode的生成。 Member Expression ...
Always end a simple statement with a semicolon. Examples: constcars = ["Volvo","Saab","Fiat"]; constperson = { firstName:"John", lastName:"Doe", age:50, eyeColor:"blue" }; General rules for complex (compound) statements: Put the opening bracket at the end of the first line. ...
2.6.2 Compound Statements 2.6.3 return Statement 2.6.4 if Statement 2.6.5 for Statement 2.6.6 while Statement 2.6.7 do Statement 2.6.8 switch Statement 2.6.9 try Statement 2.6.10 continue Statement 2.6.11 with Statement 2.6.12 Testing for Equality or Inequality 2.7 Whitespace 2.8 Do`s 2.9...
IfStmt: an if statement; use IfStmt.getCondition(), IfStmt.getThen() and IfStmt.getElse() to access its condition expression, “then” branch and “else” branch, respectively. LoopStmt: a loop; use Loop.getBody() and Loop.getTest() to access its body and its test expression, respectiv...
条件语句也被称为控制流语句(flow control statement)。 if else if语句用于在代码中做出决定。 当条件的计算结果为true,程序执行大括号内的语句。 当布尔条件的计算结果为false,大括号内的代码将不会执行。使用else语句,可以执行当条件为假时相应的代码。