javascript - 停止无限 Javascript 循环

Question

我似乎无法让以下代码停止无限循环。我对 JS 相当陌生，在 codepen 上发现了这个。它对于我正在从事的项目非常有用，但前提是我能让​​它无限期地停止循环。在输入最后一个短语后让它停止是理想的。想法？

    <style>
    body {
        background-color:#333;
        text-align: center;
    }
    * { color:#fff; text-decoration: none;}
</style>
<script>
    var TxtType = function(el, toRotate, period) {
        this.toRotate = toRotate;
        this.el = el;
        this.loopNum = 0;
        this.period = parseInt(period, 10) || 2000;
        this.txt = '';
        this.tick();
        this.isDeleting = false;
    };

    TxtType.prototype.tick = function() {
        var i = this.loopNum % this.toRotate.length;
        var fullTxt = this.toRotate[i];

        if (this.isDeleting) {
            this.txt = fullTxt.substring(0, this.txt.length - 1);
        } else {
            this.txt = fullTxt.substring(0, this.txt.length + 1);
        }

        this.el.innerHTML = '<span class="wrap">'+this.txt+'</span>';

        var that = this;
        var delta = 200 - Math.random() * 100;

        if (this.isDeleting) { delta /= 2; }

        if (!this.isDeleting && this.txt === fullTxt) {
            delta = this.period;
            this.isDeleting = true;
        } else if (this.isDeleting && this.txt === '') {
            this.isDeleting = false;
            this.loopNum++;
            delta = 500;
        }

        setTimeout(function() {
            that.tick();
        }, delta);
    };

    window.onload = function() {
        var elements = document.getElementsByClassName('typewrite');
        for (var i=0; i<elements.length; i++) {
            var toRotate = elements[i].getAttribute('data-type');
            var period = elements[i].getAttribute('data-period');
            if (toRotate) {
                new TxtType(elements[i], JSON.parse(toRotate), period);
            }
        }
        // INJECT CSS
        var css = document.createElement("style");
        css.type = "text/css";
        css.innerHTML = ".typewrite > .wrap { border-right: 0.08em solid #fff}";
        document.body.appendChild(css);
    };
</script>

    <h1>
    <a href="" class="typewrite" data-period="2000" data-type='[ "Discover", "Learn", "Train", "Prepare", "Share" ]'>
        <span class="wrap"></span>
    </a>
</h1>

Answer 1

您可以通过检查 loopNum 是否仍然小于单词数组的长度来在最后一个元素之后停止它。

if(this.loopNum < this.toRotate.length){
    setTimeout(function() {
        that.tick();
    }, delta);
}

<style>
    body {
        background-color:#333;
        text-align: center;
    }
    * { color:#fff; text-decoration: none;}
</style>
<script>
    var TxtType = function(el, toRotate, period) {
        this.toRotate = toRotate;
        this.el = el;
        this.loopNum = 0;
        this.period = parseInt(period, 10) || 2000;
        this.txt = '';
        this.tick();
        this.isDeleting = false;
    };

    TxtType.prototype.tick = function() {
        var i = this.loopNum % this.toRotate.length;
        var fullTxt = this.toRotate[i];

        if (this.isDeleting) {
            this.txt = fullTxt.substring(0, this.txt.length - 1);
        } else {
            this.txt = fullTxt.substring(0, this.txt.length + 1);
        }

        this.el.innerHTML = '<span class="wrap">'+this.txt+'</span>';

        var that = this;
        var delta = 200 - Math.random() * 100;

        if (this.isDeleting) { delta /= 2; }

        if (!this.isDeleting && this.txt === fullTxt) {
            delta = this.period;
            this.isDeleting = true;
        } else if (this.isDeleting && this.txt === '') {
            this.isDeleting = false;
            this.loopNum++;
            delta = 500;
        }
        
        if(this.loopNum < this.toRotate.length){
          setTimeout(function() {
              that.tick();
          }, delta);
        }
    };

    window.onload = function() {
        var elements = document.getElementsByClassName('typewrite');
        for (var i=0; i<elements.length; i++) {
            var toRotate = elements[i].getAttribute('data-type');
            var period = elements[i].getAttribute('data-period');
            if (toRotate) {
                new TxtType(elements[i], JSON.parse(toRotate), period);
            }
        }
        // INJECT CSS
        var css = document.createElement("style");
        css.type = "text/css";
        css.innerHTML = ".typewrite > .wrap { border-right: 0.08em solid #fff}";
        document.body.appendChild(css);
    };
</script>

    <h1>
    <a href="" class="typewrite" data-period="2000" data-type='[ "Discover", "Learn", "Train", "Prepare", "Share" ]'>
        <span class="wrap"></span>
    </a>
</h1>