for loop in Go

Go has only one looping construct, the for loop. 
The basic for loop has three components separated by semicolons:
* the init statement: executed before the first iteration
* the condition expression: evaluated before every iteration
* the post statement: executed at the end of every iteration
```
package main

import "fmt"

func main() {
	for j := 1; j < 5; j++ {
		fmt.Println(j)
	}
}
```
Note: Unlike other languages like C, Java, or JavaScript there are no parentheses surrounding the three components of the for statement and the braces { } are always required. 
The init and post statements are optional. C's while is spelled for in Go. 
```
	sum := 1
	for ; sum < 1000; {
		sum += sum
	}
```
If you omit the loop condition it loops forever, so an infinite loop is compactly expressed. 
```
	for {
		fmt.Println("loop")
		break
	}
```
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