Use the Lodash framework for data filtering and conversion
Title: Use the Lodash framework for data filtering and conversion
Summary:
Data filtering and conversion are the tasks that often encounter when dealing with large or complex data sets.Lodash is a popular JavaScript tool library that provides a large number of functions for data processing and operation.This article will introduce how to use the Lodash framework for data filtering and conversion, and provide some Java code examples.
introduction:
As the amount of data continues to increase, data processing becomes more and more important.In order to handle data more effectively, strong tools need to be used to filter and transform.Lodash is an excellent open source library that provides many practical functions and tools to make data processing simpler and convenient.In this article, we will deeply explore how to use the Lodash framework to filter and convey the data.
1. Data filtering:
1.1 Filter data according to conditions
Using the Lodash's `Filter` function, we can filter the data according to the specified conditions.Here are a Java sample code that uses Lodash for data filtering:
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.math.NumberUtils;
public class FilterExample {
public static void main(String[] args) {
List<String> data = Arrays.asList("John", "Jane", "123", "Smith", "12.34");
List<String> filteredData = data.stream()
.filter(value -> StringUtils.isNumeric(value) && NumberUtils.isParsable(value))
.collect(Collectors.toList());
System.out.println(filteredData);
// Output: [123, 12.34]
}
}
In the above examples, we used the `StringUtils.ISNUMERIC` and` NumberUtils.isparsable` functions to check whether the strings are digital types.Only the value that meets this condition will be retained.
1.2 Filter the array according to the attribute
If we have an object array and we need to filter the data according to the value of the object's attributes, we can use the `Filter` function of Lodash and the` Property` function.Here are a Java sample code filtering using Lodash for array filtering:
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
import org.apache.commons.lang3.StringUtils;
public class ObjectFilterExample {
public static void main(String[] args) {
List<Person> people = Arrays.asList(
new Person("John", 25),
new Person("Jane", 30),
new Person("Smith", 40)
);
List<Person> filteredPeople = people.stream()
.filter(person -> StringUtils.startsWith(person.getName(), "J"))
.collect(Collectors.toList());
System.out.println(filteredPeople);
// 输出: [Person{name='John', age=25}, Person{name='Jane', age=30}]
}
static class Person {
private String name;
private int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
@Override
public String toString() {
return "Person{name='" + name + "', age=" + age + "}";
}
}
}
In the above examples, we use the `StringUtils.startswith` function to check whether the` name` attribute begins with the letter "J".Only objects that meet this condition will be retained.
2. Data conversion:
2.1 Convert the array elements into a new data type
Using the Lodash's `Map` function, we can convert the elements in the array into a new data type.Here are a Java sample code using Lodash for data conversion:
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
public class MapExample {
public static void main(String[] args) {
List<String> data = Arrays.asList("1", "2", "3", "4", "5");
List<Integer> transformedData = data.stream()
.map(Integer::parseInt)
.collect(Collectors.toList());
System.out.println(transformedData);
// Output: [1, 2, 3, 4, 5]
}
}
In the above example, we used the `Integer :: PARSEINTT" method reference to convert the string to an integer type.
2.2 Properties of object attribute value conversion
If we want to convert the attribute values in the array, we can use the `Map` function of Lodash and the` Property` function.The following is a Java sample code that uses Lodash for the attribute value conversion of the object attribute value:
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
public class ObjectMapExample {
public static void main(String[] args) {
List<Person> people = Arrays.asList(
new Person("John", 25),
new Person("Jane", 30),
new Person("Smith", 40)
);
List<String> transformedNames = people.stream()
.map(Person::getName)
.collect(Collectors.toList());
System.out.println(transformedNames);
// Output: [John, Jane, Smith]
}
static class Person {
private String name;
private int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
}
}
In the above example, we use the `Person :: getName` method to quote to extract the` name` attribute values of each object in the object array.
in conclusion:
This article introduces how to use the Lodash framework for data filtering and conversion.Through the powerful functions and tools provided by Lodash, we can handle and operate data more efficiently.Regardless of data filtering or data conversion, Lodash provides us with simple and powerful solutions.It is hoped that this article can help readers better understand and use the Lodash framework for data processing.
