Why Do I Get \'undefined err\' and \'undefined user\' Errors in My Go Code?

Undefined Variable Errors in Go

When compiling a Go program, encountering "undefined err" and "undefined user" errors can be confusing for beginners. Understanding variable scoping is crucial for resolving such issues.

In the code snippet provided, the err and user variables are declared within the two if statements. This limits their scope to the respective if blocks. Hence, when user is referenced in the code block after the if-else statement, the compiler cannot find its declaration.

Update: Clarifying Variable Shadowing

In the updated code, user is declared outside the inner if block. However, the short variable declaration within the block creates a new user variable, effectively shadowing the outer user variable. Since this inner user variable is not used, the compiler issues a "user declared and not used" error.

Solution: Proper Variable Declaration

To resolve these errors, it's recommended to declare both user and err before the if-else block with a proper assignment:

Alternatively, a single line declaration can be used:

By adhering to these scoping guidelines, developers can avoid such variable-related errors and ensure proper program execution.

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