我将我的 Jquery 反转为 Javascript，但我不明白为什么这种语法有效？

Question

So my goal was to reverse this jquery into javascript. Here is the jquery

    create: function (e) {
            var $input = $(e.target);
            var val = $input.val().trim();

            if (e.which !== ENTER_KEY || !val) {
                return;
            }

            this.todos.push({
                id: util.uuid(),
                title: val,
                completed: false
            });

            $input.val('');

            this.render();
        },

Now here is the same code that I converted into javascript

create: function (e) {
            var input = e.target.value;
            var val = input.trim();

            if (e.which !== ENTER_KEY || !val) {
                return;
            }

            this.todos.push({
                id: util.uuid(),
                title: val,
                completed: false
            });

            val;

            this.render();
        },

So my Javascript code works and I understand 90% of it, but what I don't get is the 2nd to last line that just says "val;"

I went through the debugger and tried to understand it, but I don't get the reason it's placed there and why it's even necessary?

The goal is whenever I input a value to my todo-list, it will show up on my screen. The code works fine, but I don't understand the purpose of the "val;"?

Wouldn't the this.todos.push automatically add the value to my array? Or why wouldn't I add "return val;" instead?

Answer 1

I guess that previous $input.val(''); was used to empty the input field after pushing its value to the array, but in your js code it is useless that val; statement.

Furthermore, the jquery code $input.val(''); refers to the input DOM element, however in your js code the val statement just points to a local variable of your function. If you want to replicate the previous behaviour you should do something like this: input='' instead of the val;