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This is documentation for Caché & Ensemble. See the InterSystems IRIS version of this content.

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Ending Focused $Order Loops

Now let's focus the end of the loop. Again, assume the variable sub holds the non-empty substring. Then the following statement: (quit:$extract(ln,1,$length(sub))'=sub) means: “Quit if the beginning of ln doesn't match sub”. It also handles the case where $Order reaches the end of the names, where ln = "". That's because, if ln is the empty string, $Extract of ln is the empty string, and since sub isn't empty, the Quit will happen and the loop ends. Some examples are below.

SAMPLES>set sub = "J"

SAMPLES>set ln = "Jones"

SAMPLES>if $extract(ln, 1, $length(sub)) '= sub { write "No Match" }

SAMPLES>set sub = "J"

SAMPLES>set ln = "Swoboda"

SAMPLES>if $extract(ln, 1, $length(sub)) '= sub { write "No Match" }
No Match
SAMPLES>set sub = "J"

SAMPLES>set ln = "" 

SAMPLES>if $extract(ln, 1, $length(sub)) '= sub { write "No Match" }
No Match
SAMPLES>do ^loopend
Search for: J
Jones
SAMPLES>

The finished focused loop (loopend.mac) code:

loopend ; loop through last names
    read "Search for: ",sub
    set ln = $order( ^PersonI("Name", sub), -1)
    for {
        set ln = $order( ^PersonI("Name", ln) )
        quit:( $extract(ln, 1, $length(sub)) '= sub )
        write !, ln
    }
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