JavaScript to achieve text expansion and collapse effect

<ul class="outList">
        <li>
            <div>No. 5-14</div>
            <ul class="innerList">
                <li class="wordsContent">11111111111111111111111</li>
                <li class="wordsContent">22222222222222222222222</li>
                <li class="wordsContent">33333333333333333333333</li>
            </ul>
        </li>
        <li>
            <div>No. 5-15</div>
            <ul class="innerList">
                <li class="wordsContent">4444</li>
                <li class="wordsContent">55555555555555555555555555</li>
                <li class="wordsContent">6666666666666666666666666</li>
            </ul>
        </li>
</ul>

ul,li {
   list-style: none;
 }
.innerList>li {
     margin-bottom: 0.2rem;
     border-bottom: 0.01rem solid green;
     box-sizing: border-box;
     padding: 0.2rem 5% 0.7rem 3%;
     position: relative;
     margin-bottom: 0.3rem;
 }
 .open {
     font-size: 0.22rem;
     color: #12309E;
     position: absolute;
     right: 0.2rem;
     bottom: 0.1rem;
     font-weight: bold;
 }
 .close {
     font-size: 0.22rem;
     color: #12309E;
     position: absolute;
     right: 0.2rem;
     bottom: 0.1rem;
     font-weight: bold;
 }

//Expand and collapse the news var objList = $(".wordsContent"); //The li tag elements that need to be expanded and collapsed var maxNum = 5; //The length of the target value var arr = []; //All the texts that need to be expanded and collapsed objList.delegate(".open", "click", function () {
    openClose(true, this)
})
objList.delegate(".close", "click", function () {
    openClose(false, this)
})
// Initialize the package. The purpose of initialization is 1: store the original content of the Li tag; 2: hide the text that exceeds the target value function init(objList, maxNum) {
    objList.each(function (index, item) {
        arr.push($(item_).text())
        if ($(item).text().length > maxNum) {
            $(item).html($(item).text().substr(0, maxNum) + "<span class='open'>Expand<img src='./image/down^.png'/></span>")
        }
    })
}
init(objList, maxNum)

//Encapsulation function for expanding and collapsing openClose(boo, clickObj) {
    var final = '';
    arr.map(function (item, index) {
        if (item.match($(clickObj).parents(".wordsContent").text().substring(0, $(clickObj).parents(".wordsContent").text().length - 2))) {
            final = item
        }
    })
    if (boo) {
        $(clickObj).parents(".wordsContent").html(final + "<span class='close'>收起<img src='./image/up^.png'/></span>")
    } else {
        $(clickObj).parents(".wordsContent").html(final.substr(0, maxNum) + "<span class='open'>Expand<img src='./image/down^.png'/></span>")
    }
}