Javascript: gradually adding to string in each iteration?

I have a string like this that is split up:

var tokens = "first>second>third>last".split(">");

What I would like in each iteration is for it to return

Iteration 0: "last"
Iteration 1: "third>last"
Iteration 2: "second>third>last"
Iteration 3: "first>seco开发者_如何学编程nd>third>last"

I am thinking of using decrementing index for loop.... but is there a more efficient approach ?

for (int w = tokens.length-1; w == 0; w--)
{

}

var tokens = "first>second>third>last".split(">");

var out = []

while(tokens.length) {
   out.unshift(tokens.pop());
   console.log(out.join('>'))
}

OTOH this is the simplest aproach

var tokens = "first>second>third>last".split(">");

text = ''
for (w = tokens.length-1; w >= 0; w--)
{
    if(text != ''){
        text = tokens[w] + '>'+text;
    }else{
        text = tokens[w]
    }

    console.log(text);
}

You could try the following:

var tokens = "first>second>third>last".split(">"); 

for (var w = 0; w < tokens.length; w++)
{
  var substr = tokens.slice(tokens.length - 1 - w, tokens.length).join(">");
  console.log("Iteration " + w + ": " + substr)
}

You could also use join to reverse the original split. I'm not sure about efficiency but it's quite legible:

var tokens = 'first>second>third>last'.split('>');

for (var i = tokens.length - 1; i >= 0; --i) {
    var subset = tokens.slice(i).join('>');
    console.log(subset);
}

var tokens = "first>second>third>last".split(">");
var text = [];
for (var i = tokens.length; --i >= 0;) {
    text.unshift(tokens[i]);
    var str = text.join(">");
    alert(str); // replace this with whatever you want to do with str
}

Should do the trick.