62 lines
2.1 KiB
Plaintext
62 lines
2.1 KiB
Plaintext
#title RCBasic Loops [RCBasic Doc]
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#header LOOPS
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RC BASIC has 3 types of loops: <b>FOR</b>, <b>WHILE</b>, and <b>DO</b>.
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The <b>FOR</b> loop repeats a block of code and increments a counter each time it finishes the block between <b>FOR</b> and <b>NEXT</b>. When the counter reaches a certain value the <b>FOR</b> loop stops.
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#code
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For I = 1 To 5
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Print I
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Next
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#/code
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The above code will output the numbers 1 to 5 to the console. Optionally you could use the <b>STEP</b> keyword to set the number that the counter will increase by. Look at the following:
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#code
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For I = 1 To 5 Step 2
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Print I
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Next
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#/code
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The above code will output the numbers 1, 3, and 5 to the console. The <b>STEP</b> keyword increases I by 2 each time through the <b>FOR</b> loop.
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<b>WHILE</b> loops will execute a block of code while a certain condition is true.
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#code
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I = 0
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While I < 5
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Print I
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I = I + 1
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Wend
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#/code
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The above code will output the numbers 0 to 4. It will not output the number 5 because if ( I < 5 ) is false the loop will not repeat.
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The <b>DO</b> loop is similar to the <b>WHILE</b> loop with an exception. The <b>WHILE</b> loop checks for the loop condition at the start of the loop but the <b>DO</b> loop checks for the loop condition at the end of the loop. What this means is that a <b>WHILE</b> loop will never execute if the condition is false at the start but the <b>DO</b> loop is guaranteed to execute at least once before it checks if the condition was true or not.
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The <b>DO</b> loop is also unique in that it has 3 different forms. Here is the simplest form of the <b>DO</b> loop.
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#code
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Do
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Print "HELLO WORLD"
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Loop
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#/code
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The code above will continue to output HELLO WORLD to the console infinitely.
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#code
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I = 0
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Do
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Print I
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I = I + 1
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Loop While I < 5
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#/code
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The above code will output the numbers 0 to 4 to the console. This form of the <b>DO</b> loop will continue to loop while the loop condition is true.
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#code
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I = 0
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Do
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Print I
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I = I + 1
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Loop Until I = 5
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#/code
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The above code will output the numbers 0 to 4 to the console. This form of the <b>DO</b> loop will continue to loop until the loop condition is true.
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