String
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<script>//String的length属性,空格也算一个字符,注意,如果字符串中包含双字节字符也仍然会按单字符计数,但是特殊符号 标签：console,log,Number,Boolean,let,str,字符串,参数,String From： https://blog.51cto.com/u_15011997/5787404