tailieunhanh - PHP Developer's Dictionary- P15

PHP Developer's Dictionary- P15:PHP is an open source, server-side, HTML-embedded scripting language used to create dynamically generated Web pages. With an easy-to-use syntax and a large, extensible library of modules, PHP brings together the best of Perl, C++, and other languages. | PHP Developer s Dictionary The continue statement enables you to stop the execution of the current control iteration and break out to the beginning for the next iteration. The optional num value can be used to tell the parser how many control structures to continue out of. For instance if you used a continue statement inside a while statement that was inside a second while statement itself you could use continue 2 to break out of both statements. Using continue 1 which is the default implied value when not passed would simply cause you to continue out of the second or nested while statement. if num 5 continue statement will come back here if executed do something here if string go do more here string stop continue 2 breaks outside of both if statements back to first if num Syntax do code while condition Description The loop is just like the while loop except that it evaluates the condition after the execution of the loop rather than before. The effect of this is that you are guaranteed that the loop will execute at least once whereas the while loop does not allow for this. else Syntax if condition code elseif condition code else code IT-SC book 70 PHP Developer s Dictionary Description The else statement which extends the if or eiseif statements provides a default set of code to be executed if previous if or eiseif statements fail condition . The brackets around the eiseif portion of the syntax example show that this is an optional part of a statement whereas the if portion is required for the else statement. elseif Syntax if condition code elseif condition code else code Description The eiseif statement which extends the if statement provides a second evaluation on a second condition before a set of code is to be executed. This assumes that previous if or other eiseif statements fail their respective condition . The brackets around the eise portion of the syntax example show that this is an optional part of a statement whereas the if portion is .