如何创建将传递的参数视为文字的 function？

Question

I am sure that this has been asked and answered before, but I can't seem to find the right terminology to find an answer. I need to dynamically create a series of functions for later use which use certain values defined by parameters upon creation. For example:

 var i = "bar"; var addBar = function(x) { // needs to always return x + " " + "bar" return x + " " + i; } i = "baz"; var addBaz = function(x) { // needs to always return x + " " + "baz" return x + " " + i; } alert(addBar("foo")); // returns "foo baz" because i = "baz"

Is there a way I can pass i to these functions so that the original value is used, and not the reference to the variable? Thank you!

Answer 1

You would have to do something that stores the variable. Making a function that returns a function is one way to do it.

 var i = "bar"; var addBar = (function (i) { return function(x) { return x + " " + i; } }(i)); i = "baz"; var addBaz = (function (i) { return function(x) { return x + " " + i; } }(i)); console.log(addBar("foo")); console.log(addBaz("foo"));