RPG textbox? ex. Zelda games

Hi. how to make a textbox, where chars appear one at the time, only with AS. (the box and textfield can be made by hand of course).
I thought that perhaps you will have to first send the sentance you want to print out to a function, that makes the sentence into a array, with one char at all the poss, and then with a for loop print it out, with adding the next item in the array to the textfield…

Any suggestoins?