the buttons total width unequal the parent's width about swipeout HOT 3 CLOSED

//auto get children's total width method
function getBtnWidth(btns, width){
    var btnsWidth = 0;
    if(btns.length > 0) {
        btns.map(function (btn, i) {
            if (btn.style != undefined && btn.style.width != undefined && btn.style.width.indexOf("px")> 0) {
                btnsWidth += parseFloat(btn.style.width.replace("px",""));
            } else {
                btnsWidth += width / 5
            }
        })
    } else {
        btnsWidth = width / 5 * btns.length;
    }
    return btnsWidth;
}
//react didmount  set left and right buttons width
this.btnsLeftWidth = getBtnWidth(left,width);
this.btnsRightWidth = getBtnWidth(right,width);
//instead of the origin code
this.btnsLeftWidth = width / 5 * left.length;
this.btnsRightWidth = width / 5 * right.length;