Type Coercion"
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m (Created page with '{{ZUMLReferencePageHeader}} EL expressions will coerce the type automatically. Here is the summary of the coercion rules. {| border='1px' | width="100%" ! !! Boolean !! Charac…') |
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EL expressions will coerce the type automatically. Here is the summary of the coercion rules. | EL expressions will coerce the type automatically. Here is the summary of the coercion rules. | ||
| + | |||
| + | <blockquote> | ||
| + | ---- | ||
| + | '''Note:''' The coercion is also applied to function arguments. For example, <code>{c:doSomething(null)}</code> will cause <code>doSomething("")</code> being called if it expects a String object. | ||
| + | </blockquote> | ||
{| border='1px' | width="100%" | {| border='1px' | width="100%" | ||
| Line 28: | Line 33: | ||
| obj.charAt(0) | | obj.charAt(0) | ||
| Number<ref>The real class is determined at run time, such as Integer and Float.</ref>.valueOf(x) | | Number<ref>The real class is determined at run time, such as Integer and Float.</ref>.valueOf(x) | ||
| − | | | + | | obj |
|- | |- | ||
| String (empty) | | String (empty) | ||
| Line 34: | Line 39: | ||
| (char)0 | | (char)0 | ||
| 0 | | 0 | ||
| − | | obj | + | | "" (obj) |
|- | |- | ||
| null | | null | ||
| Line 52: | Line 57: | ||
<references/> | <references/> | ||
</blockquote> | </blockquote> | ||
| + | |||
| + | * The handling of an empty string and null is the same | ||
=Version History= | =Version History= | ||
Latest revision as of 11:04, 27 May 2011
EL expressions will coerce the type automatically. Here is the summary of the coercion rules.
Note: The coercion is also applied to function arguments. For example,
{c:doSomething(null)}will causedoSomething("")being called if it expects a String object.
| Boolean | Character | Number | String | |
|---|---|---|---|---|
| Boolean | obj[1] | ERROR | ERROR | obj.toString() |
| Character | ERROR | obj | (short)obj | obj.toString() |
| Number | obj | ERROR | (char)obj | obj.toString() |
| String (not empty) | Boolean.valueOf(obj) | obj.charAt(0) | Number[2].valueOf(x) | obj |
| String (empty) | false | (char)0 | 0 | "" (obj) |
| null | false | (char)0 | 0 | "" |
| Other | ERROR | ERROR | ERROR | obj.toString() |
- The handling of an empty string and null is the same
Version History
| Version | Date | Content |
|---|---|---|