javascript's switch penetration, that is, case use or logic, switch, case, break, default

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the code

function switchF() {
    
    
	let key = 5;
	
	switch (key) {
    
    
		case 1, 2, 3, 4, 5:
			console.log('工作日');
			break;
		case 6, 7:
			console.log('休息日');
			break;
		default:
			console.log('输入有误');
			break;
	}
}

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switch

MDN

switchA statement evaluates an expression , matches the expression's value to a clause, and executes the statementcase associated with that case .

switch (expression) {
     
     
	case value1:
		// 当 expression 的结果与 value1 匹配时，执行此处语句
		break;
	case value2:
		// 当 expression 的结果与 value2 匹配时，执行此处语句
		break;
	...
	case valueN:
		// 当 expression 的结果与 valueN 匹配时，执行此处语句
		break;
	default:
		// 如果 expression 与上面的 value 值都不匹配，执行此处语句
		break;
}

expression
An caseexpression used to match substatements.
case valueNoptional The clause to use for
matching . If a match is given , the statements in this clause are executed until the end of the statement or one is encountered . optional A clause; if given, this clause will be executed if the value of does not match any of the statements. A statement first evaluates its . It will then start from the first clause until it finds a clause whose expression value is equal to the value entered (using the strict operator (en-US), ===) and transfers control to Given this clause, the associated statement is executed. (If more than one match the supplied value, the first one that matches is chosen , even if these are not equal to each other.) If no clause matches, the program looks for that optional clause, and if found, it will Control is handed over to it, and the relevant statement is executed. If there is no clause, the program will continue to execute to the end. By convention, the clause is the last clause, but it doesn't need to be. The optional break statement ensures that the program immediately breaks out of the associated clause and continues executing the following statement. likeexpressioncaseexpressionvalueNcaseswitchbreak
default
defaultexpressioncase
switchexpressioncaseexpressioncasecasecase
casedefaultdefaultswitchdefault
caseswitchswitchbreakis omitted, program execution continues with switchthe next statement in the statement.

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break

MDN

breakstatement terminates the current loop, switch statement, or label statement and transfers program control flow to the statement immediately following the terminated statement.
break [label];where labelis the identifier associated with the statement label. Required if breakthe statement is not inside a loop or switch statement.
breakStatements contain an optional label that allows programs to escape a labeled statement. breakStatements need to be embedded in quoted tags. The marked statement can be any block statement; not necessarily a loop statement.
breakThe statement cannot functionbe used directly in the function body, and the statement should be nested in the current loop or statement breakto be interrupted .switchlabel

for (let i = 0; i < 9; i++) {
     
     
    if (i === 7) break;

    console.log(i);
}