15
edits
Nasal Conditionals: Difference between revisions
Jump to navigation
Jump to search
If I have undestood correctly then the example given did not illustrate the feature it was intended to, that is that the 'if' clause is an expression that reurns a value.
Red Leader (talk | contribs) m (Remove line numebrs) |
Chris-barry (talk | contribs) (If I have undestood correctly then the example given did not illustrate the feature it was intended to, that is that the 'if' clause is an expression that reurns a value.) |
||
| Line 76: | Line 76: | ||
Nasal has no "statements", which means that any expression can appear in any context. This means that you can use an if/else clause to do what the ?: (ternary operator) does in C. | Nasal has no "statements", which means that any expression can appear in any context. This means that you can use an if/else clause to do what the ?: (ternary operator) does in C. | ||
The last semicolon in a code block is optional, to make this prettier: | The last semicolon in a code block is optional, to make this prettier. First, a completely conventional implementation of the '''abs''' function: | ||
<syntaxhighlight lang="nasal"> | <syntaxhighlight lang="nasal"> | ||
| Line 86: | Line 86: | ||
} | } | ||
</syntaxhighlight> | </syntaxhighlight> | ||
This form would work as it is in "C" and, with minor adjustments for syntax, in many other languages. However, te following form would not work in "C": | |||
<syntaxhighlight lang="nasal"> | |||
var abs = func(n) { | |||
return if (n<0) | |||
{ -n } | |||
else | |||
{ n } | |||
} | |||
</syntaxhighlight> | |||
In this form the '''if''' clause is clearly an expression that yields a value. That value is the result of the last expression executed within the '''if''' clause. | |||
And for those who don't like typing, the ternary operator works like you expect: | And for those who don't like typing, the ternary operator works like you expect: | ||
| Line 92: | Line 105: | ||
var abs = func(n) { n < 0 ? -n : n } | var abs = func(n) { n < 0 ? -n : n } | ||
</syntaxhighlight> | </syntaxhighlight> | ||
This also illustrates that a function will return a value even when there is no '''return''' clause. The value returned is the value of the last expression evaluated within the function. | |||
In addition, Nasal supports braceless blocks, like they're known from C/C++ and other languages. Basically, the block ends with a semicolon, instead of being encapsulated inside a <tt>{</tt>/<tt>}</tt> pair. This means basically that the first statement (expression) after a conditional is evaluated if the condition is true, otherwise it will be ignored: | In addition, Nasal supports braceless blocks, like they're known from C/C++ and other languages. Basically, the block ends with a semicolon, instead of being encapsulated inside a <tt>{</tt>/<tt>}</tt> pair. This means basically that the first statement (expression) after a conditional is evaluated if the condition is true, otherwise it will be ignored: | ||