How do you change all classes at once?

Question

Lets say i have an class call "Rev" and this class is used multiple times... Now I have decided to add an onclick="str()" to something, so when pressed, it will do this next function:

function str(){
var allRev = document.getElementsByClassName("Rev");
allRev[ ].style.width = "900px";
}; // it will change the width

Now i want it to change all of the elements with the class name "Rev" without having to type it out eg. [0,1,2,3...] Because if this number of classes were to increase constantly, then this will become a real drag, so how can i select all of the classes at once?

Answer 1

for(var i=0; i<allRev.length; ++i){
var currRev= allRev[i];
currRev.style.width= '900px';
}

Answer 2

Thank you!