(= item1 item2 ...)
Return T if they're the same.
This function tells you whether two (or more) items are equal:
- If they are equal, the result is a T (true).
- If not, this function returns nil (false).
If the function contains more than two items, this function returns T (true) when each item to the right is equal to the item on its left. The items can be numbers or strings.
Examples
This expression
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Returns
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(= 8 8)
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T
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(= 10 10.0 10)
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T
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(= "x" "y")
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nil
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(= "door" "door")
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T
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(= "door" "door" "door")
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T
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(= 10)
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T
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NOTES
- Don't confuse the = function with the equal function. Here's the difference: The = function compares numbers and strings; the equal function compares lists.
- Both = and equal perform comparisons; neither performs the "equals" function you might expect from arithmetic, such as 1 + 2 = 3. In LISP, that service is provided by the setq function.
Tell me about...
(/= item1 item2 ...)
(< item1 item2 ...)
(<= item1 item2 ...)
(> item1 item2 ...)
(>= item1 item2 ...)
(cond (statement1 result1 ...) ...)
(eq statement1 statement2)
(if test statement1 [statement2])
(while text statement …)
LISP Compatibility
Programming Overview of LISP (LISt Processing) Language