Search results
Results from the WOW.Com Content Network
Unlike function and class names, variable names are case-sensitive. Both double-quoted ("") and heredoc strings allow the ability to embed a variable's value into the string. [13] As in C, variables may be cast to a specific type by prefixing the type in parentheses. PHP treats newlines as whitespace, in the manner of a free-form language.
PHP 5 introduced type declarations that allow functions to force their parameters to be objects of a specific class, arrays, interfaces or callback functions. However, before PHP 7, type declarations could not be used with scalar types such as integers or strings. [71] Below is an example of how PHP variables are declared and initialized.
Type errors (such as an attempt to apply the ++ increment operator to a Boolean variable in Java) and undeclared variable errors are sometimes considered to be syntax errors when they are detected at compile-time.
Arbitrarily modifying values in a database through SQL injection; the impact of this can range from website defacement to serious compromise of sensitive data. For more information, see Arbitrary code execution. Installing malware or executing malevolent code on a server by injecting server scripting code (such as PHP).
The precondition, and the definition of exception, is subjective. The set of "normal" circumstances is defined entirely by the programmer, e.g. the programmer may deem division by zero to be undefined, hence an exception, or devise some behavior such as returning zero or a special "ZERO DIVIDE" value (circumventing the need for exceptions). [4]
C does not provide direct support to exception handling: it is the programmer's responsibility to prevent errors in the first place and test return values from the functions.
An undefined variable in the source code of a computer program is a variable that is accessed in the code but has not been declared by that code. [1] In some programming languages, an implicit declaration is provided the first time such a variable is encountered at compile time. In other languages such a usage is considered to be sufficiently ...
PHP uses argc as a count of arguments and argv as an array containing the values of the arguments. [ 4 ] [ 5 ] To create an array from command-line arguments in the -foo:bar format, the following might be used: