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How are variables passed to functions in JavaScript?
/*
* JavaScript variables are always passed by value. This works as you
* expect it to when you pass primitives to functions.
*/
function add1(x) {
// We get passed a copy of x's value -- which is a number -- so we can't
// update the original variable's value
x++;
}
var x = 0;
add1(x);
console.log("x is", x); // "x is 0"
/*
* What happens when we pass an object? JavaScript still passes by value, but
* the value we're passing is a *reference* to the object.
*/
function setName(obj) {
// We get passed a copy of obj's value -- which is a reference -- so we can
// still update its properties
obj.name = "Nick";
}
var obj = {};
setName(obj);
console.log("obj.name is", obj.name); // "obj.name is Nick"
/*
* Further exploration: What about boxed objects?
*/
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