jQuery：在两个引号之间写入变量

Question

I want to create a loop for input so that the variable img get number 1 to 5 like this:

img1, img2 ... img5.

How to write $i after img?

for ($i=1;$i<=5;$i++) {

  function(data) { $('input[name="img1"]').val(data) });

}

Note: img is between two quotation mark.

it's edite:

user = $('input[name="name"]').val();
for (var i = 1; i <= 5; i++) {
  $.post("test.php", { name: user, num: i },
  function(data) {
    $('input[name="img'+i+'"]').val(data)
  });
}

Answer 1

The function you have declared in your loop seems weird. That's not valid javascript. You may try the following:

for (var i = 1; i <= 5; i++) {
    $('input[name="img' + i + '"]').val(data);
}

or if we suppose that you have defined some function:

var foo = function(data, index) {
    $('input[name="img' + index + '"]').val(data);
}

you could invoke it like this:

for (var i = 1; i <= 5; i++) {
    foo('some data ' + i, i);
}

---

UPDATE:

An interesting example was provided in the comments section:

for (var i = 1; i <= 5; i++) { 
    $.post(
        "test.php", 
        { name: username, num: i }, 
        function(data) { 
            $('input[name="img'+i+'"]').val(data);
        }
    ); 
} 

This won't work because the i variable might have changed value between the loop and the AJAX success callback. To fix this you may try the following:

for (var i = 1; i <= 5; i++) { 
    (function(index) {
        $.post(
            "test.php", 
            { name: username, num: index }, 
            function(data) { 
                $('input[name="img'+index+'"]').val(data);
            }
        ); 
    })(i);
} 

or use the $.ajax() method which allows you to pass a context to the success callback:

for (var i = 1; i <= 5; i++) { 
    $.ajax({
        url: 'test.php',
        type: 'POST',
        data: { name: username, num: i },
        context: i, // here we are defining the context
        success: function(result) {
            // since we have used the context parameter, this variable
            // here will point to the value that i had when we initiated 
            // the AJAX request
            $('input[name="img' + this + '"]').val(result);
        }
    });
} 

Answer 2

Like this:

for ($i=1;$i<=5;$i++) {

    function(data) { $('input[name="img' + $i + '"]').val(data) });

}

By the way, I'm guessing you'e coming from a PHP background, but in JavaScript it is not conventional to use $ for variable names (except sometimes for jQuery objects). So normally you'd write your code like this:

for (i=1;i<=5;i++) {

    function(data) { $('input[name="img' + i + '"]').val(data) });

}