How do combine numbers in a column with other literals to form text characters?

[#1]

dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
ar = dt << GetAsMatrix( {4} );

txt1 = "abc=" || Char( ar );

I use the above code does not match, much []

What I need is the following result:

Thanks!

txt1 = "abc=59, 61, 55, 66, 52, 60, 61, 51, 60, 61, 56, 65, 63, 58, 59, 61, 62, 65, 63, 62, 63, 64, 65, 64, 68, 64, 69, 62, 64, 67, 65, 66, 62, 66, 65, 60, 68, 62, 68, 70"

[#2]

Apparently the JSL parser is forcing the numerics into a matrix.  I suggest you turn the issue into JMP support for their feedback.  In the mean time, here is a workaround:

names default to here(1);
// Open Data Table: big class.jmp
// → Data Table( "big class" )
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
ar = dt << GetAsMatrix( 4 );

txt1 = "abc=" || char(ar[1]);
for(i=2,i<=nitems(ar), i++,
	txt1 = txt1 || ", " || char(ar[i])
);
show(txt1);

[#3]

Thank Jim!

[#4 · Accepted solution]

If you know it's just going to be a matrix, you could just lop off the []. 

txt1 = "abc=" || Substitute(Char( ar ), "[", "", "]", "");