Commodore PET - Strings; Concatenating Strings

S$
-----.
ISITlulvlwlx/YIzl
STRINGS
CONCATENATING STRINGS
Recall that when creating strings the PET will accept alphabetic, graphie.
and numeric characters. or combinations of these,
While handling strings, it may
be useful to connect one or more strings together into a single string by linking
them end to end in a chain-like fashion:
String 1
String 2
String '3
String 41 ... __ S_t_ri_ng_1 _ ...... __ S_tr_in_g_2_ ...... i.o-_S_t_ri_ng_3_ ....
Suppose. for example. we want to create one large string, Z$, containing the
alphabet A through
Z. By linking together the la st character of A$, shown below,
with the first character of J$. and the last character of J$ to the first character of
S$, Z$ may be created:
A$ J$
~---
IAIslcloIEIFIGIHIC'P!KILlMlNlolploIRI
z$IAISlcloIEIFIGIHIIIJIKILIMINlolploIRlsITluIVlWlXlylzl
Concatenating alphabetic strings. such a A$, J$ and S$, may be done using
one simple statement:
Z$=A$+J$+S$
The arithmetic operator "+" adds the contents of numeric variables or
the numbers themselves. But when used with strings the "+" serves as a
linkage sign to concatenate the strings together. Table 5-1 summarizes the ad-
dition of strings and numbers.
A
word of caution: strings cannot be separated or broken apart in the
same fashion as they are concatenated; they cannot be "subtracted" the
way they are "added." For instance, to create string X$ containing the contents
of J$ and
S$ from our original strings A$, J$, S$, and Z$, it would be incorrect to
type:
X$=Z$-A$ Incorrect
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