Break D3 Each Loop Without a flag

问题

Consider the following code:

circle.each(function (d) {
    //...code
});

How can I break the loop? Is there a natural D3 way to break out of an each loop? I mean without a flag as follows:

var flag = false;
circle.each(function (d) {
    if (flag) return;
    if (someCondition) flag = true;
    //...code
});

I've tried returning false inside the if statement but it did not work (thought that maybe this would work the same as jquery.each but I was wrong):

circle.each(function (d) {
    if (someCondition) return false; //Not working
    //...code
});

回答1:

No, there is not. Take a look at the each source code https://github.com/mbostock/d3/blob/78e0a4bb81a6565bf61e3ef1b898ef8377478766/src/selection/each.js.

You may be able to throw an exception to break the loop, but unless your case is really "exceptional", using an exception is probably more confusing than helpful.

回答2:

you can do following

var flag = false;
circle.some(function (d) {
    if (flag) return true;
});

来源：https://stackoverflow.com/questions/32566989/break-d3-each-loop-without-a-flag