在使用jQuery时候，我们经常会看到或者使用到方法链，例如：
$("#p1").css("color","red").slideUp(2000).slideDown(2000);
这段代码的意思是选择器选择id为p1的html标签，颜色变红，之后slideup，再slidedown。
自然是可以将这几个方法分开写，但是不分开的话不仅有很好的易读性，代码量也会有减少，那么何乐而不为？
这种调用函数的方式在jQuery中称为“Chaining”，原理也很简单：能够chaining的方法调用后返回对象本身即可。
下面用java代码做个演示：
不使用chaining：
Persion.java：
public class Persion {
private int id;
private String name;
private String phoneNumber;
private String address;
public Persion() {
}
public void setId(int id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
}
public void setPhoneNumber(String phoneNumber) {
this.phoneNumber = phoneNumber;
}
public void setAddress(String address) {
this.address = address;
}
public void printId() {
System.out.println(this.id);
}
public void printName() {
System.out.println(this.name);
}
public void printPhoneNumber() {
System.out.println(this.phoneNumber);
}
public void printAddress() {
System.out.println(this.address);
}
}
Test.java：
public class Test {
public static void main(String[] args) {
Persion persion1 = new Persion();
persion1.setId(3);
persion1.setName("John");
persion1.setPhoneNumber("1111111");
persion1.setAddress("US");
persion1.printId();
persion1.printName();
persion1.printPhoneNumber();
persion1.printAddress();
}
}
使用chaining：
Persion.java：
public class Persion {
private int id;
private String name;
private String phoneNumber;
private String address;
public Persion() {
}
public Persion setId(int id) {
this.id = id;
return this;
}
public Persion setName(String name) {
this.name = name;
return this;
}
public Persion setPhoneNumber(String phoneNumber) {
this.phoneNumber = phoneNumber;
return this;
}
public Persion setAddress(String address) {
this.address = address;
return this;
}
public Persion printId() {
System.out.println(this.id);
return this;
}
public Persion printName() {
System.out.println(this.name);
return this;
}
public Persion printPhoneNumber() {
System.out.println(this.phoneNumber);
return this;
}
public Persion printAddress() {
System.out.println(this.address);
return this;
}
}
Test.java：
public class Test {
public static void main(String[] args) {
Persion persion1 = new Persion();
persion1.setId(3).setName("John")
.setPhoneNumber("1111111").setAddress("US");
persion1.printId()
.printName()
.printPhoneNumber()
.printAddress();
}
}
好诡异的感觉~哈哈！