JavaScript Switch statement is used to execute different set of statements based on different conditions. It is similar to If-Else statement, but excels in code simplicity and works greatly with numbers, characters and Strings. Syntax </> Copy switch(expression){ case value_1 : // set of st...
Syntax switch(expression) { casen: code block break; casen: code block break; default: defaultcode block } Parameter Values ParameterDescription expressionRequired. Specifies an expression to be evaluated. The expression is evaluated once. The value of the expression is compared with the values of ...
The switch statement is used to perform different actions based on different conditions.The JavaScript Switch StatementUse the switch statement to select one of many blocks of code to be executed.Syntaxswitch(expression) { case n: code block break; case n: code block break; default: default ...
Syntax of the switch...case Statement switch(expression) {casevalue1:// code block to be executed// if expression matches value1break;casevalue2:// code block to be executed// if expression matches value2break; ... default:// code block to be executed// if expression doesn't match any...
babel 编译的第一步是把源码 parse 成抽象语法树 AST (Abstract Syntax Tree),后续对这个 AST 进行转换。(之所以叫抽象语法树是因为省略掉了源码中的分隔符、注释等内容) AST 也是有标准的,JS parser 的 AST 大多是 estree 标准,从 SpiderMonkey 的 AST 标准扩展而来。babel 的整个编译流程都是围绕 AST 来的,...
Switch Theswitchstatement evaluates an expression and executes code as a result of a matching case. The basic syntax is similar to that of anifstatement. It will always be written withswitch () {}, with parentheses containing the expression to test, and curly brackets containing the potential ...
原文:7. JavaScript’s Syntax 译者:飞龙 协议:CC BY-NC-SA 4.0 JavaScript 的语法相当简单。本章描述了需要注意的事项。 语法概述 本节让你快速了解 JavaScript 的语法是什么样子的。 以下是五种基本类型的值: 布尔值: true false 数字: 1023 7.851 ...
Useswitchto select one of many blocks of code to be executed Syntax Theifstatement specifies a block of code to be executed if a condition is true: if(condition) { // block of code to be executed if the condition is true } Theelsestatement specifies a block of code to be executed if...
“This ‘switch’ should be an ‘if’.”:“此处’switch’应该是’if’.”, “All ‘debugger’ statements should be removed.”:“请删除’debugger’的语句”, “‘{a}’ is not a statement label.”:“‘{a}’不是一个声明标签.”,
switch 语句会对表达式进行求值,并将表达式的值与一系列 case 子句进行匹配,一旦遇到与表达式值相匹配的第一个 case 子句后,将执行该子句后面的语句,直到遇到 break 语句为止。若没有 case 子句与表达式的值匹配,则会跳转至 switch 语句的 default 子句执行。