# Formatting strings review

A convenient way to format strings in Go is by using the standard library's [fmt.Sprintf()](https://pkg.go.dev/fmt#example-Sprintf) function. It's a string interpolation function, similar to JavaScript's built-in template literals. The `%v` substring uses the type's default formatting, which is often what you want.

### Default values

```go
const name = "Kim"
const age = 22
s := fmt.Sprintf("%v is %v years old.", name, age)
// s = "Kim is 22 years old."
```

The equivalent JavaScript code:

```js
const name = 'Kim'
const age = 22
s = `${name} is ${age} years old.`
// s = "Kim is 22 years old."
```

### Rounding floats

```go
fmt.Printf("I am %f years old", 10.523)
// I am 10.523000 years old

// The ".2" rounds the number to 2 decimal places
fmt.Printf("I am %.2f years old", 10.523)
// I am 10.53 years old
```

## Assignment

We need better error logs for our backend developers to help them debug their code.

Complete the `getSMSErrorString()` function. It should return a string with this format:

```
SMS that costs $COST to be sent to 'RECIPIENT' can not be sent
```

* `COST` is the cost of the SMS, always showing the price formatted to 2 decimal places.
* `RECIPIENT` is the stringified representation of the recipient's phone number

*Be sure to include the $ symbol and the single quotes*