Why Can't I Use `:=` Short Variable Declaration Outside of a Function in Go?

Understanding "<=: Short Variable Declaration Issue

In Go, the &= Short variable declaration syntax is typically used to declare and initialize variables within function bodies. However, attempting to use this syntax outside of a function can result in the compilation error "expected declaration, found 'IDENT' item."

Cause of the Error

The error message indicates that the compiler expected a declaration (such as var) but encountered the IDENT item (which represents an identifier) instead. In the provided code, the line:

item := &memcache.Item {
    Key:   "lyric",
    Value: []byte("Oh, give me a home"),
}

tries to declare and initialize the item variable using the &= syntax outside a function, which is not allowed.

Resolution

To resolve this error, you can do either of the following:

1. Declare the variable within a function: If you want to use the &= syntax, move the variable declaration inside a function, such as:

func MyFunction() {
    item := &memcache.Item {
        Key:   "lyric",
        Value: []byte("Oh, give me a home"),
    }

    // Do something with item
}

2. Declare the variable globally: If you want to use the variable outside of any function (globally), declare it using the var keyword:

var item = &memcache.Item {
    Key:   "lyric",
    Value: []byte("Oh, give me a home"),
}

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