How can i display a statement only once in a loop which is running 4 times?

Question

Hi, 
 I have the following code where i want to display the message "Hello World" only once in a loop . what condition i should write? 
 
 a!localVariables( 
 a!forEach( items: {1,2,3,4}, expression: { concat("Hello "," World") 
 } 
 ) )

dastagirid756 · Answer

In order to display a message once in a loop, first decide the condition for displaying a message. Then implement the condition inside the loop. 
 For example, if I want to display the Hello World when I reach second iteration or item, follow the below code snippet 
 a!forEach( items: { 1, 2, 3, 4 }, expression: { if( fv!item = 2, concat("Hello ", " World"), null ) } ) 
 
 To avoid null values in the results: 
 reject( fn!isnull, a!forEach( items: { 1, 2, 3, 4 }, expression: { if( fv!item = 2, concat("Hello ", " World"), null ) } ) )