Short Frequent Answers
Difference (last change) (Author, normal page display)
Changed: 10c10
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*Background: dynamic arrays (e. g. strings) and array slices are implemented as 8-Byte-(length, pointer)-dupels. |
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*Background: dynamic arrays (e. g. strings) and array slices are implemented as 8-Byte-(length, pointer)-dupels. So, the length is stored "in" the reference, or belongs to it. (but no capacity like in c++ vectors is stored). |
MicroFAQ
Here is a short list of common answers to common questions asked about D. Reading the list should help programmers (particularly C/C++) quickly get to know D.
- Strings are not null-terminated but hold explicit length information. Therefore you need to use %.*s not %s in printf, or just use writef!
- Save yourself a bunch of trouble and don't use printf(). It's not type-safe, it doesn't play nice with D's strings, and it has no concept of classes (so it can't call Object.toString()). Use D's writef() or writefln() instead, which are in the std.stdio module.
- Background: dynamic arrays (e. g. strings) and array slices are implemented as 8-Byte-(length, pointer)-dupels. So, the length is stored "in" the reference, or belongs to it. (but no capacity like in c++ vectors is stored).
- Visibility (public/private/protected) is on the module level not the scope/block level. There is also a package protection.
- To create an instance of a class you need to use the word *new* otherwise the reference will be null.
- Casting in D requires that the word *cast* be appended in front of the bracketed conversion type. ie cast(int)
- If your switch(expr) statement doesn't have a default case and expr doesn't match any of the cases, an exception is thrown when in debug mode.
- Source code must be in either UTF-8 (or other Unicode), or ASCII (a subset of UTF-8). Specifically, ISO-8859-1 ("Latin-1") will *not* work!
- The console / terminal must be set to UTF-8, or non-ASCII characters will not be handled correctly.
- Comparing an object reference like: "if (object == null)" will crash. You must use "if (object is null)". This operator is necessary, because == could be overloaded.
- Checking for a key in an AA like: "if(array[key])" will create it if it's missing, or give an error as of dmd 0.126. You must use "if(key in array)".
- In a do/while loop, the keyword "continue" will jump to the condition, not the start of the loop body.