# Variables

> Source: https://learn-go.org/variables/
> Part of Learn Go, free to read.

A variable is a name given to a storage area that the programs can manipulate. The name of a variable can be composed of letters, digits, and the underscore character. It must begin with either a letter or an underscore.

### Numbers

They are arithmetic types and they represents following values throughout the program.
a) integer types
b) floating point

To define an integer, use the following syntax:

```go
var a int = 4
var b, c int
b = 5
c = 10
fmt.Println(a)
fmt.Println(b + c)
```

To define a floating point number, you may use one of the following notations:

```go
var d float64 = 9.14
fmt.Println(d)
```

### Strings

Strings in Go are defined with double quotes.

```go
var s string = "This is string s"
fmt.Println(s)
```

The difference between the two is that using double quotes makes it easy to include apostrophes (whereas these would terminate the string if using single quotes)

```go
var s string = "Don't worry about apostrophes"
fmt.Println(s)
```

### Shorthand Declaration

The `:=` notation serves both as a declaration and as initialization.
`foo := "bar"` is equivalent to `var foo string = "bar"`

```go
a := 9
b := "golang"
c := 4.17
d := false
e := "Hello"
f := `Do you like golang, so far?`
g := 'M'

fmt.Println(a)
fmt.Println(b)
fmt.Println(c)
fmt.Println(d)
fmt.Println(e)
fmt.Println(f)
fmt.Println(g)
```