Question

imagine I type the following code into the interpreter:

var1 = 'zuuzuu'

now suppose i type:

var1.find('a')

the interpreter returns -1. which i understand because the substring has not been found. but please help me understand this:

var1.find('a' or 'z') #case 1

returns -1

but

var1.find('a' and 'z') #case 2

returns 0

According to the logic in my head the interpreter should return -1 for case 2 because the substrings ‘a’ AND ‘z’ are NOT located in the string. While in case 1, 0 should be returned since ‘z’ is a substring.

thanks

Answer 1

Expression 'a' or 'z' always yields 'a'. Expression 'a' and 'z' always yields 'z'. It’s not some kind of DSL for making queries into containers, it’s a simple boolean expression (and find is called with its result). If you want to say “is there ‘a’ or ‘z’ in the string”, you need to do

var1.find('a') != -1 or var.find('z') != -1

And for the second one (both ‘a’ and ‘z’ in the string):

var1.find('a') != -1 and var.find('z') != -1