5 ForLoop

5 ForLoop - for loops for Do exactly the same thing as...

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Unformatted text preview: for loops for Do exactly the same thing as while loops Use when you know the exact number of times you want to count Parts of the loop Initialize (counter) Condition (boolean test) Update (iteration expression) 1 for loop 1 Start with this 2 Test this if false Exit for (int i = 0; i < 10; i++){ for (int i = 0; i < 10; i++){ 3 Run the code 4 Do this 5 Return to #2 #4 & #5 are “invisible } 2 A while loop A int count = 1; while(count < 4) { println("count is " + count); println("count count++; count++; } 3 A while loop A int count = 1; while(count < 4) { println("count is " + count); println("count count++; count++; } /* Output is count is 1 count is 2 count is 3 */ 4 A while and a for loop that do the A exactly the same thing int count = 1; while(count < 4) { println("count is " + println("count count++; count++; } Is the same as for(int count = 1;count { println("count is " + println("count } count); < 4;count++) count); 5 Notice both have the same 3 parts Notice both have the same 3 parts int count = 1; while(count < 4) { println("count is " + println("count count++; count++ } Is the same as for(int count = 1;count { println("count is " + println("count } count); < 4;count++) count); 6 Why both? Why both? Some programmers prefer the for loop since it uses fewer lines of code Most beginning programmers find the while loop easier to understand Good Style: Use for loops only when you know in advance how many times you want the loop to run. In all other circumstances use a while loop. 7 Practice Quiz Question Practice Quiz Question Write a program that uses two for loops to produce the following output xxxxxx 10 9 8 7 6 5 4 3 2 1 8 ...
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This note was uploaded on 01/13/2012 for the course CS 12 taught by Professor Ma during the Spring '08 term at UC Davis.

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