Javascript 无法设置属性'；innerHTML'；循环中未定义的

我想更改按钮的颜色，但我可以通过任何方法（样式、innerHtml等）获得此消息

        <div class="a-section backGround layer">
        </div>
        <div class="a-section layer">
            <div class="a-row dealDetailContainer">
                <div class="a-row a-spacing-mini">
                    <div class="a-row a-spacing-unspecified">
                        <span class="a-size-mini a-color-base hiddenCss">&nbsp;</span>
                        <span class="a-size-mini a-color-base badgeSkew"></span>
                    </div>
                </div>
                <div class="a-row stackToBottom">

                    <div class="a-row a-spacing-medium">

                        <span class="a-declarative">

                            <span class="a-button a-button-normal a-button-span12 a-button-primary fixedWidth210">
                                <span class="a-button-inner">
                                <button class="a-button-text a-text-center" type="button">
                                        Add to Cart
                                </button>

                                </span>
                            </span>
                        </span>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

错误：未捕获类型错误：无法设置未定义的属性“颜色”

        <div class="a-section backGround layer">
        </div>
        <div class="a-section layer">
            <div class="a-row dealDetailContainer">
                <div class="a-row a-spacing-mini">
                    <div class="a-row a-spacing-unspecified">
                        <span class="a-size-mini a-color-base hiddenCss">&nbsp;</span>
                        <span class="a-size-mini a-color-base badgeSkew"></span>
                    </div>
                </div>
                <div class="a-row stackToBottom">

                    <div class="a-row a-spacing-medium">

                        <span class="a-declarative">

                            <span class="a-button a-button-normal a-button-span12 a-button-primary fixedWidth210">
                                <span class="a-button-inner">
                                <button class="a-button-text a-text-center" type="button">
                                        Add to Cart
                                </button>

                                </span>
                            </span>
                        </span>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

html: `

        <div class="a-section backGround layer">
        </div>
        <div class="a-section layer">
            <div class="a-row dealDetailContainer">
                <div class="a-row a-spacing-mini">
                    <div class="a-row a-spacing-unspecified">
                        <span class="a-size-mini a-color-base hiddenCss">&nbsp;</span>
                        <span class="a-size-mini a-color-base badgeSkew"></span>
                    </div>
                </div>
                <div class="a-row stackToBottom">

                    <div class="a-row a-spacing-medium">

                        <span class="a-declarative">

                            <span class="a-button a-button-normal a-button-span12 a-button-primary fixedWidth210">
                                <span class="a-button-inner">
                                <button class="a-button-text a-text-center" type="button">
                                        Add to Cart
                                </button>

                                </span>
                            </span>
                        </span>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

添加到购物车

`

        <div class="a-section backGround layer">
        </div>
        <div class="a-section layer">
            <div class="a-row dealDetailContainer">
                <div class="a-row a-spacing-mini">
                    <div class="a-row a-spacing-unspecified">
                        <span class="a-size-mini a-color-base hiddenCss">&nbsp;</span>
                        <span class="a-size-mini a-color-base badgeSkew"></span>
                    </div>
                </div>
                <div class="a-row stackToBottom">

                    <div class="a-row a-spacing-medium">

                        <span class="a-declarative">

                            <span class="a-button a-button-normal a-button-span12 a-button-primary fixedWidth210">
                                <span class="a-button-inner">
                                <button class="a-button-text a-text-center" type="button">
                                        Add to Cart
                                </button>

                                </span>
                            </span>
                        </span>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

js:

        <div class="a-section backGround layer">
        </div>
        <div class="a-section layer">
            <div class="a-row dealDetailContainer">
                <div class="a-row a-spacing-mini">
                    <div class="a-row a-spacing-unspecified">
                        <span class="a-size-mini a-color-base hiddenCss">&nbsp;</span>
                        <span class="a-size-mini a-color-base badgeSkew"></span>
                    </div>
                </div>
                <div class="a-row stackToBottom">

                    <div class="a-row a-spacing-medium">

                        <span class="a-declarative">

                            <span class="a-button a-button-normal a-button-span12 a-button-primary fixedWidth210">
                                <span class="a-button-inner">
                                <button class="a-button-text a-text-center" type="button">
                                        Add to Cart
                                </button>

                                </span>
                            </span>
                        </span>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

var-button=document.getElementsByClassName=（“.a-button-primary.a-button-text”）；
var i；
对于（i=0；i正如@Heretic的评论中所指出的，您的语法不正确。我发现的另一个问题是，您的循环超出了返回元素的长度。在
for
循环中，您使用的是
，正如@Heretic的评论中所指出的，您的语法不正确。我发现的另一个问题是，您的循环超出了返回元素的长度ed元素。在
for
循环中，您使用的是
GetElementsByCassName=（
？您的控制台中应该会出现语法错误……而且
GetElementsByCassName
采用类的名称，而不是选择器（即，没有点）。我在没有点的情况下尝试了它，但没有效果。请关闭大写锁定。在大多数在线社区中，使用所有大写字母书写都被认为是大喊大叫。
getElementsByClassName=（
？您的控制台中应该会出现语法错误……而且
getElementsByClassName
采用类的名称，而不是选择器（即，没有点）.我在没有dot的情况下试过，但没用。请关闭大写锁定。在大多数在线社区中，使用大写字母写作被认为是大喊大叫。