我有以下代码,在其中我尝试迭代创建标签元素newDay
(我在其中添加newDayIcon
,最后添加到newWeekSet
:
...
console.log(dict);
var newLine = document.createElement('div').classList.add('list-group-item');
var newButton = document.createElement('div').classList.add('add-button');
var newTemp = document.createElement('a');
var newName = document.createElement('a').classList.add('name-font');
var newWeekSet = document.createElement('div').classList.add('right-align');
Object.entries(dict).forEach(function([key, value]) {
console.log(key, value);
var newDay = document.createElement('label').classList.add('day-font');
var newDayIcon;
console.log(newDay);
newDay.textContent = key.charAt(0);
if (value) {
newDayIcon = document.createElement('i').classList.add('far', 'fa-check-circle', 'fa-xs')
newDayIcon.style.color = 'Blue';
}
else {
newDayIcon = document.createElement('i').classList.add('far', 'fa-times-circle', 'fa-xs')
newDayIcon.style.color = 'Orange';
}
newDay.appendChild(newDayIcon);
newWeekSet.appendChild(newDay);
});
var newMoveIcon = document.createElement('i').classList.add('fas', 'fa-bars');
newButton.id = 'schedule-'+i++;
newLine.append(newButton, newName, newWeekSet, newMoveIcon);
dashboard.appendChild(newLine);
}
具有以下电流输出:
Friday: null,
Monday: Object {
EndTime: "12:50 A.M.",
StartTime: "12:55 A.M."
},
Saturday: null,
Sunday: Object {
EndTime: "12:50 A.M.",
StartTime: "12:55 A.M."
},
Thursday: null,
Tuesday: null,
Wednesday: null
}
"Sunday" Object {
EndTime: "12:55 A.M.",
StartTime: "12:59 A.M."
}
undefined
TypeError: undefined is not an object (evaluating 'newDay.textContent = key.charAt(0)')
我似乎无法弄清楚为什么无法以这种方式创建newDay
元素-是否有特定的原因无法使用?
document.createElement('label').classList.add('day-font');
不返回值。在使用classList.add
结果的任何地方,实际上都是将var分配给undefined
。 我在您脚本的很多地方都看到了这种模式。我建议在尝试像这样操作之前,创建元素并将其值分配给var:
var newDay = document.createElement('label');
newDay.classList.add('day-font');
// do even more things to newDay if you want.
在任何地方创建新元素,然后稍后尝试更新该元素的地方,都需要像这样将步骤分开。
让我知道您是否有任何疑问!