You asked about how it compares with C, so here's a C version:

#include <stdio.h>
#include <string.h>

char *undef;
char *def_empty = "";
char *def = "foo bar";

void check(char *t) {
    if (t) {
        if (strlen(t)) {
            printf("Defined loc=%p, val='%s'\n", t, t);
        }
        else {
            printf("Empty string: loc=%p\n", t);
        }
    }
    else {
        printf("Undefined (null ptr)\n");
    }
}

int main(int, char **) {
    check(undef);
    check(def_empty);
    check(def);
    return 0;
}

[download]

It gives us:

$ ./a.exe
Undefined (null ptr)
Empty string: loc=0x4020e5
Defined loc=0x4020e6, val='foo bar'

[download]

...roboticus

When your only tool is a hammer, all problems look like your thumb.

In reply to Re: defined vs null string by roboticus
in thread defined vs null string by Anonymous Monk

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