How to Avoid "Assignment to Entry in Nil Map" Runtime Error When Working with Slices of Maps in Go?

Runtime Error: "Assignment to Entry in Nil Map"

When working with slices of maps, it's crucial to avoid creating a slice of nil maps, which will result in a runtime error like the one you encountered.

To create a slice of maps, follow these steps:

1. Make a slice of maps with the make() function:

   <code class="go">invs := make([]map[string]string, length)</code>

2. Populate the maps within the slice:

   <code class="go">for i := 0; i < length; i++ {
       invs[i] = map[string]string{"Id": inv_ids[i], "Investor": inv_names[i]}
   }</code>

Consider using a Composite Literal:

Instead of creating a nil map and assigning values to it, you can use a composite literal, which combines all the key-value pairs into a single expression:

<code class="go">invs[i] = map[string]string{"Id": inv_ids[i], "Investor": inv_names[i]}</code>

Alternative Approach Using a Struct:

An alternative and more idiomatic approach is to define a struct to represent an investor and use a slice of structs:

<code class="go">type Investor struct {
    Id   int
    Name string
}

invs := make([]Investor, length)

for i := 0; i < length; i++ {
    invs[i] = Investor{Id: i, Name: "John" + strconv.Itoa(i)}
}</code>

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