in the C language, there is no string type, the string is an array of characters, but there is a string type in js, so in js Why the string can also be obtained through the subscript in parentheses, and what is the difference between str [I] and str.charAt (i) ?
js We usually create String
var str = "abc"
when manipulating a string, it is converted to a string object
var str = new String ('abc');
jsString
str[0]String0
charAtStringapi
:
when the subscript does not exist, str [index] returns undefined (undefined) and str.charAt (index) returns "(empty string)
The string is an array-like object with a length attribute, which can be valued by a numeric key (0mem1).
str [I] and str.charAt (i) are essentially the same, but str.charAt (i) is more standard
is no different. There's nothing wrong with it. The standard rule is yes. Let me ask you why strings in js can use both single quotation marks and double quotation marks.
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