duansha8115 2018-05-25 10:27
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大数PHP的比较失败了

I was reading an article and I found this example:

// Prints bool(true)
var_dump('9223372036854775807' == '9223372036854775808');

// Prints bool(false)
var_dump('9223372036854775807' ==='9223372036854775808');

Anyone can explain me why?

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  • dongshuo1856 2018-05-25 10:32
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    As of PHP 5.4.4 this is no longer an issue.

    The reason why this is happening, is because of type-juggling. In the first example you're checking if the two values are equal AFTER type-juggling so effectively it's comparing two string types.

    And in the other example you are checking whether the two values are identical, as in the same type and the exact same value.

    Check this.

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