What is the difference between doing a string cast and strval in php ?
在php中执行字符串转换和strval有什么区别?
strval($value);(string)$value;
3 个解决方案
#1
19
http://www.php.net/manual/en/language.types.string.php#language.types.string.casting
A value can be converted to a string using the (string) cast or the strval() function.
可以使用(string)强制转换或strval()函数将值转换为字符串。
Looks the same to me.
看起来和我一样。
#2
5
One is a function call, the other one is an internal typecast. Without having checked, I'd guess the latter one is faster by few cycles, but shouldn't really make a difference.
一个是函数调用,另一个是内部类型转换。如果没有经过检查,我猜测后者会在几个周期内更快,但不应该真正有所作为。
#3
3
They are generally interchangeable because PHP uses automatic type conversion and a variable's type is determined by the context in which the variable is used.
它们通常是可互换的,因为PHP使用自动类型转换,变量的类型由使用变量的上下文决定。
Some differences are that strval($var) will return the string value of $var while (string) $var is explicitly converting the "type" of $var during evaluation.
一些差异是strval($ var)将返回$ var的字符串值而(string)$ var在评估期间显式转换$ var的“type”。
Also, from the manual, for strval() $var "may be any scalar type or an object that implements the __toString method. You cannot use strval() on arrays or on objects that do not implement the __toString method."
另外,从手册中,对于strval()$ var,可以是任何标量类型或实现__toString方法的对象。不能对数组或不实现__toString方法的对象使用strval()。“
As mentioned by @Lars (string) is generally faster.
正如@Lars所提到的(字符串)通常更快。
#1
19
http://www.php.net/manual/en/language.types.string.php#language.types.string.casting
A value can be converted to a string using the (string) cast or the strval() function.
可以使用(string)强制转换或strval()函数将值转换为字符串。
Looks the same to me.
看起来和我一样。
#2
5
One is a function call, the other one is an internal typecast. Without having checked, I'd guess the latter one is faster by few cycles, but shouldn't really make a difference.
一个是函数调用,另一个是内部类型转换。如果没有经过检查,我猜测后者会在几个周期内更快,但不应该真正有所作为。
#3
3
They are generally interchangeable because PHP uses automatic type conversion and a variable's type is determined by the context in which the variable is used.
它们通常是可互换的,因为PHP使用自动类型转换,变量的类型由使用变量的上下文决定。
Some differences are that strval($var) will return the string value of $var while (string) $var is explicitly converting the "type" of $var during evaluation.
一些差异是strval($ var)将返回$ var的字符串值而(string)$ var在评估期间显式转换$ var的“type”。
Also, from the manual, for strval() $var "may be any scalar type or an object that implements the __toString method. You cannot use strval() on arrays or on objects that do not implement the __toString method."
另外,从手册中,对于strval()$ var,可以是任何标量类型或实现__toString方法的对象。不能对数组或不实现__toString方法的对象使用strval()。“
As mentioned by @Lars (string) is generally faster.
正如@Lars所提到的(字符串)通常更快。