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Check the dimensions of an array. > *Note:* Do not confuse the `DIM()` function with the `DIM` statement for declaring variables. * Check Number of Dimensions ```sbsyntax dimensions% = DIM(array) ``` |* Input | Description | | `array` | The array to check. | |* Output | Description | | `dimensions%` | The number of dimensions `array` has. | `dimensions%` will be 1 for a 1D array, 2 for a 2D, etc. * Check Length of a Dimension ```sbsyntax length% = DIM(array, dimension%) ``` |* Input | Description | | `array` | The array to check. | | `dimension%` | The dimension of array to check the length of. | |* Output | Description | | `length%` | The length of `dimension%` in `array`. | The value `dimension%` corresponds to the "/n/ th dimension," i.e. 0 is the first dimension in `array`. `length%` will the size of that specific dimension. * Examples ```sb4 'check dimensions of A DIM A[10,2] PRINT DIM(A) '2 PRINT DIM(A,0) '10 ``` * Notes ** No OUT Form It is impossible to call `DIM()` in `OUT` form. Though it appears to be a proper "function", it is a special case of the `DIM` keyword that behaves like one. Take the following example: ```sb4 DIM A VAR B DIM A OUT B ``` When the parser reaches line 3, it tries to parse it as a variable declaration, because it sees the `DIM` keyword and then an identifier. If `A` was declared earlier (in this example it was, and in most cases it would be) this line will trigger `Duplicate variable`, because this is treated as a `DIM` statement. The parser doesn't even have a chance to reach the `OUT` keyword. If `A` was not declared previously (maybe you aren't using strict mode) this line will still throw a `Syntax error`, because using `OUT` after a variable declaration is meaningless. So, in all cases, this must be called like a single-return function (which, in most cases, is what you would do anyway.) ```sb4 DIM A VAR B=DIM(A) ``` Perhaps this also explains the lack of an `OUT` form that returns the lengths of all dimensions, e.g. `DIM A OUT B,C,D,E`.
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