string equality Reason

Ask, why does PHP think that two strings are equal?
if ("03E-004611" = = "36E-008026") echo ' equal ';

Reply to discussion (solution)

This post was last edited by xuzuning on 2014-02-08 17:10:29

Var_dump ("03E-004611" = = "36E-008026"); BOOL (TRUE) Var_dump (03E-004611, 36E-008026); Float (0) float (0) var_dump ("03E-004611" = = = "36E-008026"); BOOL (FALSE)

A string of numbers that is converted to a number before being compared.

Ask, why does PHP think that two strings are equal?
if ("03E-004611" = = "36E-008026") echo ' equal ';
Upstairs explanation is not very perfect, because you are using double quotation marks, and you are a number, in double quotation marks can be executed, this is a feature of PHP, if you change into single quotation marks that is not the same

Because E is 10 of the operation "03E-004611" converted into a number of points when the number is infinitely close to 0, 3*pow (10,-4611), up to such a high precision, so it is 0.

Long knowledge.

Ask, why does PHP think that two strings are equal?
if ("03E-004611" = = "36E-008026") echo ' equal ';
Upstairs explanation is not very perfect, because you are using double quotation marks, and you are a number, in double quotation marks can be executed, this is a feature of PHP, if you change into single quotation marks that is not the same
It's the same with single quotes.

This has nothing to do with whether in single double quotes!
It's just a cognitive problem with the science counting method.

You say I've tried 90a-904611 and 36E-008026, these two strings are not equal
36E-008026 of them are scientific notation, and 90a-904611 is not

So the numbers need to be compared by string, not numeric.

It's a pose.

