javascript里类似select case该如何用

　　 

switch Statement<br>
Enables the execution of one or more statements when a specified expression's value matches a label.<br>
<br>

switch (expression) {<br>
&nbsp;&nbsp;&nbsp;case label :<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;statementlist<br>
&nbsp;&nbsp;&nbsp;case label :<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;statementlist<br>
&nbsp;&nbsp;&nbsp;...<br>
&nbsp;&nbsp;&nbsp;default :<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;statementlist<br>
} <br>
<br>
Arguments<br>
expression<br>
<br>
The expression to be evaluated.<br>
<br>
label<br>
<br>
An identifier to be matched against expression. If label === expression, execution starts with the statementlist immediately after the colon, and continues until it encounters either a break statement, which is optional, or the end of the switch statement.<br>
<br>
statementlist<br>
<br>
One or more statements to be executed.<br>
<br>
Remarks<br>
Use the default clause to provide a statement to be executed if none of the label values matches expression. It can appear anywhere within the switch code block. <br>
<br>
Zero or more label blocks may be specified. If no label matches the value of expression, and a default case is not supplied, no statements are executed.<br>
<br>
Execution flows through a switch statement as follows: <br>
<br>
Evaluate expression and look at label in order until a match is found. <br>
If a label value equals expression, execute its aclearcase/" target="_blank" >ccompanying statementlist. <br>
Continue execution until a break statement is encountered, or the switch statement ends. This means that multiple label blocks are executed if a break statement is not used. <br>
If no label equals expression, go to the default case. If there is no default case, go to last step. <br>
Continue execution at the statement following the end of the switch code block. <br>
Example<br>
The following example tests an object for its type. <br>
<br>
function MyObject() {<br>
...}<br>
<br>
switch (object.constructor){<br>
&nbsp;&nbsp;&nbsp;case Date:<br>
&nbsp;&nbsp;&nbsp;...<br>
&nbsp;&nbsp;&nbsp;case Number:<br>
&nbsp;&nbsp;&nbsp;...<br>
&nbsp;&nbsp;&nbsp;case String:<br>
&nbsp;&nbsp;&nbsp;...<br>
&nbsp;&nbsp;&nbsp;case MyObject:<br>
&nbsp;&nbsp;&nbsp;...<br>
&nbsp;&nbsp;&nbsp;default: <br>
&nbsp;&nbsp;&nbsp;...<br>
}<br>
Requirements<br>
Version 3<br>
<br>

原文转自：http://www.ltesting.net