TypeError：插入第一个值时无法读取null的属性'push'

So I have been trying to wrap my head around this for hours now and can't seem to figure it out, i've tried the different solutions that people have discussed here in Stackoverflow such as checking if there is an array and if not make one and what not, but I still get the error. TypeError: Cannot read property 'push' of nullSo I have been trying to wrap my head around th