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I need a little help regarding creating a global map variable in Go. What I have done is as follows:
package ... import( ... ) ... type ir_table struct{ symbol string value string } var ir_MAP map[int]ir_table Since I am not initializing the map, I am getting a nil pointer dereference error. What must I do to use this variable globally? Or, if this is not a correct way to do this, please guide me.
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While it is possible to define a global variable by just omitting var (assuming there is no local variable of the same name), doing so generates an implicit global, which is a bad thing to do and would generate an error in strict mode. window is available only in browsers.
The global Keyword Normally, when you create a variable inside a function, that variable is local, and can only be used inside that function. To create a global variable inside a function, you can use the global keyword.
Talend provides the globalMap Object where both Talend and you can store and retrieve data. This is a great place to create your global variables as well as retrieving important information about your executing Job. globalMap is my preference for storing global data that is specific to a particular Job.
You need to initialize it with an empty map:
var ir_MAP = map[int]ir_table{} or, as "the system" suggested:
var ir_MAP = make(map[int]ir_table) The problem is that the zero value of a map is nil, and you can't add items to a nil map.
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You can directly initialize a map like this:
var Romans = map[byte]int{ 'I': 1, 'V': 5, 'X': 10, 'L': 50, 'C': 100, 'D': 500, 'M': 1000, } If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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