Use jquery to implement the inverse selection function

In web page production, we usually need to select one or more HTML elements for operation or display. Sometimes, we need to perform the reverse operation, that is, reverse selection. Today, we will introduce a method to implement the inverse selection function using jQuery.

First, we need to understand the selectors in jQuery. In jQuery, the $ symbol represents jQuery, and we can select any element on the page by using the $() function.

Common jQuery selectors are:

1. Element selector: $("element")
2. ID selector: $("#id")
3. Class selector: $(".class")
4. Attribute selector: $("[attrName='value']")
5. Child element selector: $ ("parentSelector > childSelector")
6. Descendant element selector: $("ancestorSelector descendantSelector")

After understanding the basic usage of selectors, we can start to implement inverse selection Functional.

1. Get all elements

First, we need to get all the elements in the page. You can use the * selector here to select all elements. The code is as follows:

var all = $("*");

2. Bind click event

Then, we need to bind a click event to each element. When the element is clicked, the selection is inverted. We can use the each() method to iterate through all selected elements and add a click event to each element. The code is as follows:

all.each(function() {
  $(this).click(function() {
    $(this).toggleClass("selected");
  });
});

Here, we use the toggleClass() method to switch the selected class of the element. If the element originally contains the selected class, this method will remove it, otherwise it will add the class.

3. Implement the inverse selection function

Finally, we need to implement the inverse selection function, that is, select all unselected elements and unselect all selected elements. We can traverse all elements when the inverse selection function is triggered to determine whether the element contains the selected class. If not, add the class; if it already contains the class, remove the class. The code is as follows:

function inverseSelect() {
  all.each(function() {
    if (!$(this).hasClass("selected")) {
      $(this).addClass("selected");
    } else {
      $(this).removeClass("selected");
    }
  });
}

Finally, we can integrate the above codes together to get the complete anti-selection function implementation code:

$(document).ready(function() {
  var all = $("*");

  all.each(function() {
    $(this).click(function() {
      $(this).toggleClass("selected");
    });
  });

  function inverseSelect() {
    all.each(function() {
      if (!$(this).hasClass("selected")) {
        $(this).addClass("selected");
      } else {
        $(this).removeClass("selected");
      }
    });
  }

  $("#inverseBtn").click(function() {
    inverseSelect();
  });
});

The above code includes selecting all elements, binding click events, and implementing The complete process of deselecting functions and setting button trigger events. We just need to add a button to the HTML and set its ID to inverseBtn, and the inverse function can be triggered by clicking the button.

Summary:

jQuery is a powerful JavaScript library with rich built-in APIs. We can use it to implement many interesting functions, such as the inverse selection function introduced today. Through the introduction of this article, you have learned how to use jQuery selectors, bind events and implement the inverse selection function. I hope it will be helpful to you.

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