# Common Mistakes¶

• forgetting to create the array - only declaring it (int[ ] nums;)
• using 1 as the first index not 0
• using array.length as the last valid index in an array, not array.length - 1.
• using array.length() instead of array.length (not penalized on the free response)
• using array.get(0) instead of array[0] (not penalized on the free response)
• going out of bounds when looping through an array (using index <= array.length). You will get an ArrayIndexOutOfBoundsException.
• jumping out an loop too early by using one or more return statements before every value has been processed.
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