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When strings are initialised each string item is enclosed in quotes: 29 The Java Language String[ } languages = {"Java", "C++ ", "Object Pascal"}; If you want to change an array element you do so by specifying its name and the element that you want to change: languages[2} = "Visual Basic"; A common problem in C++ is that if you define an array as having, for example, 10 elements and you try and write to an element greater than this at run time, unexpected problems can happen. It may cause the program to halt and give an error message or the program may continue having overwritten a piece of data that happened to be at the place in the memory than you wrote to.

Command line arguments for applications Some applications need to have information passed to them at run-time. These are called command line arguments. For example if you have a sort application you may have to specify the name of the file to be sorted and the name of the output file containing the sorted information. In Java programs there is only one parameter passed to the application: • args: an array of strings containing the arguments. The number of arguments can be found from using the length( ) method of the array.

The two expressions below have the same effect, but the first one is much clearer: if age >= 18 voter( ); if J(age < 18) voter ( ); When a sequence of mathematical operations is carried out, the order in which this is done can be very important, for example: c =9 + 6/3; 53 Branching and Looping If the addition is carried out first the expression becomes 15/3 = 5. If the division is done first, it becomes 9+2 = 11. In this case the division would be done first, since the division operator has a higher precedence than the addition operator.