Pointers and references: Difference between revisions
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There are not other possible operations on Fortran "pointers" (at least before Fortran 2003). |
There are not other possible operations on Fortran "pointers" (at least before Fortran 2003). |
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=={{header|FreeBASIC}}== |
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<lang freebasic>' FB 1.05.0 Win64 |
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Type Cat |
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name As String |
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age As Integer |
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End Type |
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Type CatInfoType As Sub (As Cat Ptr) |
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Sub printCatInfo(c As Cat Ptr) |
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Print "Name "; c->name, "Age"; c-> age |
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Print |
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End Sub |
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' create Cat object on heap and store a pointer to it |
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Dim c As Cat Ptr = New Cat |
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' set fields using the pointer and the "crow's foot" operator |
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c->name = "Fluffy" |
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c->age = 9 |
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' print them out through a procedure pointer |
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Dim cit As CatInfoType = ProcPtr(printCatInfo) |
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cit(c) |
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Delete c |
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c = 0 |
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Dim i As Integer = 3 |
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' create an integer pointer variable and set it to the address of 'i' |
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Dim pi As Integer Ptr = @i |
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'change the variable through the pointer |
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*pi = 4 |
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'print out the result |
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print "i ="; *pi |
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'create a reference to the variable i |
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Dim ByRef As Integer j = i |
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' set j (and hence i) to a new value |
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j = 5 |
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' print them out |
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Print "i ="; i, "j ="; j |
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Sleep</lang> |
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{{out}} |
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<pre> |
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Name Fluffy Age 9 |
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i = 4 |
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i = 5 j = 5 |
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</pre> |
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=={{header|Go}}== |
=={{header|Go}}== |
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Go has pointers but no pointer arithmetic. In general it disallows many operations that are common in other languages but have proven to be common sources of programming errors. |
Go has pointers but no pointer arithmetic. In general it disallows many operations that are common in other languages but have proven to be common sources of programming errors. |
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