The sleep() function delays execution of the current script for short time period.Syntaxsleep(sec)Parameterssec− The number of seconds to delay the script.ReturnThe sleep() function returns zero on success.Example Live DemoOutputThe following is the output.02:54:50 02:54:52 02:54:57

The ignore_user_abort() function sets whether a remote client can abort the running of a script.Syntaxignore_user_abort(setting)Parameterssetting − True ignores user aborts in a script (the script will continue to run). This is false by default i.e. client aborts will cause the script to stop runningReturnThe ignore_user_abort() function returns previous value of ... Read More

The filter_input() function gets a name of external variable and filters it optionally.Syntaxfilter_input(type, var, filtername, options)Parameterstype − There are five types of inputs to check i.e. INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV.var − The name of variable.filtername − The name of filter to get ID.options − Specifies options to use.ReturnThe ... Read More

The filter_has_var() function is used to check that variable of specified type exists or not.Syntaxfilter_has_var(type, var)Parameterstype − There are five types of inputs to check i.e. INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV.var − The name of variable.ReturnThe filter_has_var() function returns true on success and false on failure.ExampleThe following is an ... Read More

The FILTER_VALIDATE_FLOAT constant validates a value as a float number.ReturnThe FILTER_VALIDATE_FLOAT constant does not return anything.Example Live DemoOutputThe following is the output.float(291.9)

The filter_var() function is used to filter a variable with a specified filter.Syntaxfilter_var(variable, filter, options)Parametersvariable − The name of variable.filter − The name of filter to get ID.options − Specifies options to use.ReturnThe filter_var() function returns filtered data on success, or false on failure.Example Live DemoRead More

To reach on a conclusion on quantified statements, there are four rules of inference which are collectively called as Inference Theory of the Predicate Calculus.Table of Rules of InferenceRule of InferenceName$$\begin{matrix} \forall x P(x) \ \hline \therefore P(y) \end{matrix}$$Rule US: Universal Specification$$\begin{matrix} P(c) \text { for any c} \ \hline ... Read More

The cite attribute of the element is used to set a URL that specified the reason to insert the text. Following is the syntax −Above, we have set url, which is the address to the document explaining the reason to insert the text. Let us now see an example ... Read More

Clear to Send (CTS) is a control frame employed in the medium access control (MAC) layer protocol IEEE 802.11 RTS/CTS. The protocol uses the concept of Multiple Access with Collision Avoidance (MACA) in wireless networks. The RTS/CTS (Request to Send / Clear to Send) mechanism aims to reduce frame collisions ... Read More

The tag defines the heading of an HTML document. It is used to group the - headings.Note − The tag introduced and deprecated in HTML5. It is dropped from W3C HTML5 specification.Following is the syntax − Let us now see an example to ... Read More