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Introduction to GoLang
course content

Course Content

Introduction to GoLang

Introduction to GoLang

1. Getting Started
What is Go Programming Language?Hello WorldComments in GoBasics of VariablesModifying Variable ValuesConstantsBasics of Operators & ExpressionsChallenge: Hello WorldChallenge: Comments in GoChallenge: Basics of VariablesChallenge: Constants
2. Data Types
IntegersFloating-Point NumbersBooleansRunesStringsBasic Type CastingString FormattingChallenge: String Formatting Practice
3. Control Structures
Comparison OperatorsConditional StatementsConditional ChainingLogical OperatorsSwitch StatementFor LoopBreak StatementChallenge: Practicing For Loop
4. Functions
Declaring and Defining FunctionsLocal and Global ScopesPassing Data into the FunctionsReturn Values from FunctionsMultiple Return ValuesPassing Functions as ArgumentsChallenge: Reviewing Concepts of Functions
5. Arrays and Slices
Declaring ArraysAccessing and Modifying Array ElementsSlicesLength vs CapacityMulti-Dimensional ArraysIterating Over ArraysPassing Variable Number of Arguments into FunctionsPassing Arrays into FunctionsChallenge: Finding the Largest Element in a Grid
6. Intro to Structs & Maps
Creating StructsCreating Instances of StructsData in StructsWhat are Maps?Map Declaration and InitializationAccessing Map ValuesDeleting Keys From MapsChallenge: Creating a Structure

book
Accessing Map Values

We can access the value corresponding to a key in a map using the following syntax:

go

index

copy

              
1

            
mapName["keyName"]

For example:

go

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1234567891011121314

            
package main
import "fmt"

func main() {
	prices := map[string]int {
		"apple": 100,
		"banana": 120,
		"peach": 170,
	}

	fmt.Println(prices["apple"]) // Output: 100
	fmt.Println(prices["banana"]) // Output: 120
	fmt.Println(prices["peach"]) // Output: 170
}

The expression prices["apple"] essentially references the memory location where the value 100 is stored; hence, it acts like a variable. Therefore, we can edit the value stored at that key using the = operator:

go

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12345678910111213

            
package main
import "fmt"

func main() {
	prices := map[string]int {
		"apple": 100,
		"banana": 120,
		"peach": 170,
	}

	prices["apple"] = 160
	fmt.Println(prices["apple"]) // Output: 160
}

We can use the same assignment syntax to create a new key in the map:

python

If the provided keyName doesn't exist in the map, it will create and add a new key to the map with the assigned value.

go

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1234567891011121314151617

            
package main
import "fmt"

func main() {
	
	numbers := map[string]int {
		"one": 1,
		"two": 2,
		"three": 3,
	}
	
	fmt.Println(numbers) // Output: map[one:1 three:3 two:2]
	
	numbers["four"] = 4
	
	fmt.Println(numbers) // Output: map[four:4 one:1 three:3 two:2]
}
question mark

What will be the output of the following code?

Select the correct answer

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Thanks for your feedback!

Section 6. Chapter 6
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