Empty string vs null

mark mark at qtrac.eu
Tue Feb 4 07:44:08 UTC 2020


Just found this post by Mark Parker that explains: 
https://forum.dlang.org/post/gvveit$10i5$1@digitalmars.com

// test.d
import std.stdio;
import std.string;

void main()
{
     report(null, "null");
     report("");
     report("x");
}

void report(const string x, const string name=null) {
     writeln("\nx     = \"", name is null ? x : name, "\"");
     writeln("null  = ", x is null);
     writeln("\"\"    = ", x == "");
     writeln("empty = ", x.empty);
}

Output:

x     = "null"
null  = true
""    = true
empty = true

x     = ""
null  = false
""    = true
empty = true

x     = "x"
null  = false
""    = false
empty = false


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