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Loop variables captured by the func literal

Reports references to loop variables from within func literals in defer and go statements. Such variables might have unexpected values because they are not copied to func literals, and the func literals in defer and go are not executed immediately.

For more information about closures and goroutines, refer to What happens with closures running as goroutines? at go.dev.

Example:

for _, v := range []string{"a", "b", "c"} { go func() { fmt.Println(v) // output will likely be `c c c`, not `a b c` }() }
for _, v := range []string{"a", "b", "c"} { v := v // `v` is copied now go func() { fmt.Println(v) }() }

Note the analyzer only checks defer and go statements when they are the last statement in the loop body. Otherwise, the analysis might produce false detections.

Inspection Details

By default bundled with:

GoLand 2024.1, Qodana for Go 2024.1,

Can be installed with plugin:

Go, 241.SNAPSHOT

Last modified: 12 March 2024