看看string是否开始匹配另一个字符串

Question

I have a list of keywords in an array and when the user types one of them correctly, I run the pass() function. I check if what the user has typed after each key has been typed ( on key up ) is equal to anything in the array.

I do this by on each key up, use a for loop to iterate through the array and if it matches at item in the array, then run the pass function, but if it is longer or equal to in length and not equal to an item in the array and is the end of the array has been reached then run a fail function.

Here is my code:

var keywords = new Array('', 'help', 'search', 'clock', 'folio', 'pong', 'simon');
for(var i=0; i<=(keywords.length)-1; i++){
if($('#code').val()===keywords[i]){
    pass(i);
}
else if(($('#code').val().length>=keywords[i].length) && (i === (keywords.length)-1)){
    fail();
}
}

Now, the problem that I am encountering is premature fail() execution. When the user types one of the longer keywords, the moment it is longer than one of the shorter keywords fail is executed.

Also, for some research on typing 'help' and 'search' both pass and fail run ?

Anyway, what I am wondering is there is there a way to improve my code to better so what I am trying to do and properly work?

Is it possible to check if what the user is typing is matching one of the keywords and if it looks like they are spelling one of they keywords then not fail(), but the moment they mess up and spell something that is equal to length, but not the keyword then fail().

For example: sear would cause a fail in my previous code, but in what I am now trying to do it wouldn't until the user types something like searck.

Answer 1

You need to only call fail() when the for loop is done and nothing matched.

I can't tell what you were trying to accomplish with the else if logic. Here's a version that calls fail() only if there were no matches. It also takes the $('#code').val() out of the for loop for efficiency sakeand breaks out of the for loop when it finds a match since there's no reason to continue.

var keywords = new Array('', 'help', 'search', 'clock', 'folio', 'pong', 'simon');
var val = $('#code').val();
var fullMatch = false, partialMatch = false;

for (var i = 0; i < keywords.length; i++) {
    if (val === keywords[i]) {
        fullMatch = true;
        pass(i);
        break;
    } else if (val && !partialMatch) {
        if (keywords[i].indexOf(val) === 0) {
           partialMatch = true;
        }
    } 
}
if (!fullMatch && !partialMatch) {
    fail();
}