1. The basic types of transfer mode
<script>
var a = 1;
function test(x) {
x = 10;
console.log(x);
}
test(a); // 10
console.log(a); // 1
</script>
2. complex type passed by reference
<script>
var a = {
a: 1,
b: 2
};
function test(x) {
x.a = 10;
console.log(x);
}
test(a); // { a: 10, b: 2 }
console.log(a); // { a: 10, b: 2 }
</script>
3. Press the share transfer
complex type This happens characteristic, the reason is in the transfer process, a first target to produce a copy of a,
this is not a copy of a copy of a deep cloned, a copy of the object a point to the same address pointing to heap memory.
Thus the modification in the body of the function x = 10 is only a copy of the modified, a target does not change. However, if the modification is a modification xa = 10 both point to the same pile of memory, which is the object will be a influences.
Some people say this feature is called passing references, there is a saying called the press share transfer