How does an underscore in front of a variable in a cocoa objective-c class work?

If you use the underscore prefix for your ivars (which is nothing more than a common convention, but a useful one), then you need to do 1 extra thing so the auto-generated accessor (for the property) knows which ivar to use. Specifically, in your implementation file, your synthesize should look like this: @synthesize missionName = … Read more

Curly braces in string in PHP

This is the complex (curly) syntax for string interpolation. From the manual: Complex (curly) syntax This isn’t called complex because the syntax is complex, but because it allows for the use of complex expressions. Any scalar variable, array element or object property with a string representation can be included via this syntax. Simply write the … Read more

Check if an image is loaded (no errors) with jQuery

Check the complete and naturalWidth properties, in that order. function IsImageOk(img) { // During the onload event, IE correctly identifies any images that // weren’t downloaded as not complete. Others should too. Gecko-based // browsers act like NS4 in that they report this incorrectly. if (!img.complete) { return false; } // However, they do … Read more

How can I pad a String in Java?

Since Java 1.5, String.format() can be used to left/right pad a given string. public static String padRight(String s, int n) { return String.format(“%-” + n + “s”, s); } public static String padLeft(String s, int n) { return String.format(“%” + n + “s”, s); } … public static void main(String args[]) throws Exception { System.out.println(padRight(“Howto”, … Read more