PHP exit,exit (0), exit (1), exit (' 0 '), exit (' 1 '), Die,return difference

Source: Internet
Author: User



Die (' 1 ') Die () and exit () are all abort script execution functions; the two names of Exit and die refer to the same function, and die () is the alias of the exit () function. The function accepts only one parameter, either a value returned by a program or a string, or a parameter without input, and the result has no return value.



Reference: Although the two are the same, there are usually subtle selectivity in use.



When passed to the exit and Die function, the value of 0 o'clock means that the execution of the script is terminated prematurely, usually with the name exit ().


 
echo "1111";
exit(0);
echo "2222";


When a program goes wrong, it can be passed a string, which is output on the system terminal, usually using the name Die ().


$ fp = fopen ("./ readme.txt", "r") or die ("Cannot open this file");
// In this case, if the fopen function is called and returns a Boolean value of false, die () will immediately terminate the script and print immediately
// The string passed to it, "Can say one or two words before death".


The same die (' 1 ') also goes through exit (' 1 '), Output 1


 
echo "begin";
die (‘1‘);
echo "end"; // output begin1





Exit (1) Do not output content, end program


echo "begin";
exit (1);
echo "end";
// output begin 





Exit (0) do not output content, end program


 
echo "begin";
exit(0);
echo "end"; //output begin





Exit (' 0 ') output 0 and end the program


 
echo "begin";
exit(‘0‘);
echo "end"; // output begin0





Exit (' 1 ') Output 1 and end the program


 
echo "begin";
exit(‘1‘);
echo "end"; //output begin1





return value, the subsequent program is not executed, the value is not output


echo "begin";
return 1;
echo "end";
// output begin, the value of return is not output to the screen, but is returned to the previous layer 





Summarize:


return is the return value, die is stopped when encountering an error, exit is a direct stop, and the subsequent code is not run, and exit () can display the content. return is a pure return value, but it will not run subsequent code exit (0): Run the program normally and exit the program; exit (1): Exit the program due to abnormal operation;
The difference between exit, exit (0), exit (1), exit ('0'), exit ('1'), die, return in PHP


PHP exit,exit (0), exit (1), exit (' 0 '), exit (' 1 '), Die,return difference


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