str.length; (vs) str.length()

Question

I had a cannot find symbol error when I used length() for a string inside a function and got rid of it when i used length. I need to know what is the reason for this?

code:

//this got cannot find symbol error
static int[] matchingStrings(String[] strings, String[] queries) {
        int n=queries.length();
        int ns=strings.length();
        int res[]=new int[n];
//this ran 
static int[] matchingStrings(String[] strings, String[] queries) {
        int n=queries.length;
        int ns=strings.length;
        int res[]=new int[n];

There is no method `length()` for an array (hence that symbol isn't found) but there is a property `length` (hence that works). — CherryDT, Aug 18 '20 at 13:36
Get length of queries array: `queries.length` - Get length of first string inside of queries array: `queries[0].length()` — CherryDT, Aug 18 '20 at 13:38
Note that `length` is an attribute for `String[]` (and arrays in general), but a method `length()` for `String`, because otherwise it would not be confusing enough. — tobias_k, Aug 18 '20 at 13:39

score 2 · Accepted Answer · answered Aug 18 '20 at 13:40

2

You are confused:

For array: array.length; For Strings: string.length();

For arrays, length is not considered a method, it is a constant (an attribute)(that's why there is no ()).

answered Aug 18 '20 at 13:40

Ralph Aouad

414
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str.length; (vs) str.length()

1 Answers1