HP 39gII - Page 284

274 Programming
program, if variables a and b are not declared and X is
90, then expr("2X+a+b") returns 180+a+b.
When used in tandem with other functionality built-in to
the HP39gII, the expr command can be used in powerful
ways. For example, you could build functions up out of
strings and export these functions so they can be used
throughout the calculator.
string Syntax: string(object);
Returns a string representation of the object. The result
varies depending on the type of object. For example,
string(2/3); results in string("2/3")
Examples:
inString Syntax: inString(str1,str2)
Returns the index of the first occurrence of str2 in str1.
Returns 0 if str2 is not present in str1. Note that the first
character in a string is a position 1.
Examples:
inString("vanilla","van") returns 1.
inString ("banana","na") returns 3
inString("ab","abc") returns 0
String Result
string(2/3) "2/3"
string(2.0/3) "0.666666666667"
string(F1), when F1(X)
= COS(X)
"(X)->COS(X)"
string(L1) when L1 =
{1,2,3}
"1,2,3"
string(M1) when M1 = "[1,2,3],[4,5,6]"
123
456