javascript - Solution to the cumulative assignment problem of addition and equal in js

Question

In the first picture, I can understand that the value of a after += in variable a is 18. In the second picture, I first created a style tag (the first red line), and then assigned new attributes and values ​​to the style tag. If I can use equals for the first assignment, but I have to use plus equals for subsequent assignments...

漂亮男人 · Answer

The first one is the accumulation of numbers, and the second accumulation is equivalent to splicing strings. You can change it to a template string, which is more convenient to process, as shown below.

var cssNode=document.createElement('style');
var middle='b';
cssNode.innerHTML='a';
cssNode.innerHTML+= `--- ${middle}----`;
cssNode.innerHTML+='c';
console.log(cssNode.innerHTML);
//输出： a--- b----c

女神的闺蜜爱上我 · Answer

The first one is numbers, + is equivalent to addition.

The second type is string, + is equivalent to connection.

女神的闺蜜爱上我 · Answer

I don’t quite understand what you want to express, so I’ll just answer the last sentence: a+=b is equivalent to a = a + b

黄舟 · Answer

cssNode.innerHtml += "..."; is equivalent to cssNode.innerHtml = cssNode.innerHtml + "...". And every time innerHtml is changed, the redrawing of the html element will be resent (strictly speaking, including reflow and redrawing, corresponding to reflow and repaint in English)
This is what is asked to be displayed in order

If you want to display it once finally, define a variable such as myInnerHtml, do += operation on it, and finally give cssNode.innerHtml = myInnerHtml

typecho · Answer

First define a character number variable, and finally assign it to innerHtml