BEGIN and END Blocks In Ruby (original) (raw)
Last Updated : 25 Sep, 2019
Every Ruby source file can run as the BEGIN blocks when the file is being loaded and runs the END blocks after the program has finished executing. The BEGIN and END statements are different from each other. A program may contain multiple BEGIN and END blocks. If there is more than one BEGIN statement in a program, they are executed in the order If there is more than one END statement, they are executed in the reverse of the order. the first END one is executed last. An open curly brace always come after BEGIN and END keyword.Syntax:
BEGIN{ Code . . .} END{ . . .}
Below is the example to better understand:Example :
Ruby `
Ruby Program of BEGIN and END Block
BEGIN {
BEGIN block code
puts "BEGIN code block" }
END {
END block code
puts "END code block" }
MAIN block code
puts "GeeksForGeeks"
`
Output :
BEGIN code block GeeksForGeeks END code block
In above example, as we can see BEGIN block code will execute first then Main block code will be executed after that END block code will be executed.Example :
Ruby `
Ruby Program of BEGIN and END Block
BEGIN block
BEGIN {
a = 4 b = 3 c = a + b
BEGIN block code
puts "This is BEGIN block code" puts c
}
END block
END {
a = 4 b = 3 c = a * b
END block code
puts "This is END block code" puts c }
Code will execute before END block
puts "Main Block"
`
Output :
This is BEGIN block code 7 Main Block This is END block code 12
**Note :**If an END statement is used in a loop Then it is executed more than once.