redeclaration

Is there any purpose to redeclaring JavaScript variables?

由 旧时模样 提交于 2019-11-27 07:48:23
问题 I am new to JavaScript. <html> <body> <script type="text/javascript"> var x=5; document.write(x); document.write("<br />"); var x; document.write(x); </script> </body> </html> Result is: 5 5 When x is declared the second time it should be undefined, but it keeps the previous value. Please explain whether this redeclaration has any special purpose. 回答1: You aren't really re-declaring the variable. The variable statement in JavaScript, is subject to hoisting, that means that they are evaluated

Is it possible to overwrite a function in PHP

由 余生长醉 提交于 2019-11-26 11:51:40
Can you declare a function like this... function ihatefooexamples(){ return "boo-foo!"; }; And then redeclare it somewhat like this... if ($_GET['foolevel'] == 10){ function ihatefooexamples(){ return "really boo-foo"; }; }; Is it possible to overwrite a function that way? Any way? Edit To address comments that this answer doesn't directly address the original question. If you got here from a Google Search, start here There is a function available called override_function that actually fits the bill. However, given that this function is part of The Advanced PHP Debugger extension, it's hard to

Is it possible to overwrite a function in PHP

由 假如想象 提交于 2019-11-26 03:34:41
问题 Can you declare a function like this... function ihatefooexamples(){ return \"boo-foo!\"; }; And then redeclare it somewhat like this... if ($_GET[\'foolevel\'] == 10){ function ihatefooexamples(){ return \"really boo-foo\"; }; }; Is it possible to overwrite a function that way? Any way? 回答1: Edit To address comments that this answer doesn't directly address the original question. If you got here from a Google Search, start here There is a function available called override_function that
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