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There Is No While Loop in Go

Most programming languages have a concept of a while loop. Because Go allows for the omission of sections of a for loop, a while loop is just a for loop that only has a CONDITION.

for CONDITION {
  // do some stuff while CONDITION is true
}

For example:

plantHeight := 1
for plantHeight < 5 {
  fmt.Println("still growing! current height:", plantHeight)
  plantHeight++
}
fmt.Println("plant has grown to ", plantHeight, "inches")

Which prints:

still growing! current height: 1
still growing! current height: 2
still growing! current height: 3
still growing! current height: 4
plant has grown to 5 inches

Go also allows you to omit the condition entirely to create an infinite loop:

for {
  // do some stuff forever
}

Assignment

We have an interesting new cost structure from our SMS vendor. They charge exponentially more money for each consecutive text we send! Let's write a function that calculates how many messages we can send in a given batch given a costMultiplier and a maxCostInPennies.

In a nutshell, the first message costs a penny, and each message after that costs the same as the previous message multiplied by the costMultiplier.

There is a bug in the code! Add a condition to the for loop to fix the bug. The loop should stop when balance is equal to or less than 0. So what condition should the for loop evaluate?