Question

我正在尝试创建一种方法来比较两个arraylist buttonresourceIds＆amp; buttonresourceIds2。我想比较它们以确定它们是否共享按钮元素。然后返回＆＃34;数字＆＃34;他们分享的元素。

OBJ

它给了我结果，但循环不断重复。我错过了什么吗？

Answer 1

你不需要两个循环来做到这一点，一个循环足以解决它

ArrayList<String>> buttonresourceIds = new ArrayList<String>>();
ArrayList<String>> buttonresourceIds2 = new ArrayList<String>>();
int common=0;
for(int j=0;j<buttonresourceIds2.size();j++){
    if(buttonresourceIds.contains(buttonresourceIds2.get(j))){
        System.out.println("Exist : "+buttonresourceIds2.get(j));
        common++;
    }else{
        System.out.println("Not Exist : "+buttonresourceIds2.get(j));
    }
}
return common;

Answer 2

见下面的代码：

{{#models}}
{{#model}}
//
// {{classname}}.swift
//
// Generated by swagger-codegen
// https://github.com/swagger-api/swagger-codegen
//

import Foundation

{{#description}}

/** {{description}} */{{/description}}
{{#isArrayModel}}
public typealias {{classname}} = [{{arrayModelType}}]
{{/isArrayModel}}
{{^isArrayModel}}
{{#isEnum}}
public enum {{classname}}: {{dataType}} {
{{#allowableValues}}{{#enumVars}}    case {{name}} = "{{{value}}}"
{{/enumVars}}{{/allowableValues}}
    func encodeToJSON() -> Any { return self.rawValue }
}
{{/isEnum}}
{{^isEnum}}
{{#vars.isEmpty}}
public typealias {{classname}} = {{dataType}}
{{/vars.isEmpty}}
{{^vars.isEmpty}}
open class {{classname}}: NSObject, NSCoding {{#parent}}{{{parent}}}{{/parent}}{{^parent}},JSONEncodable{{/parent}} {

{{#vars}}
{{#isEnum}}
    public enum {{enumName}}: {{^isContainer}}{{datatype}}{{/isContainer}}{{#isContainer}}String{{/isContainer}} { {{#allowableValues}}{{#enumVars}}
        case {{name}} = {{#isContainer}}"{{/isContainer}}{{#isString}}"{{/isString}}{{{value}}}{{#isString}}"{{/isString}}{{#isContainer}}"{{/isContainer}}{{/enumVars}}{{/allowableValues}}
    }
{{/isEnum}}
{{/vars}}
{{#vars}}
{{#isEnum}}
    {{#description}}/** {{description}} */
    {{/description}}public var {{name}}: {{{datatypeWithEnum}}}{{^unwrapRequired}}?{{/unwrapRequired}}{{#unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}{{#defaultValue}} = {{{defaultValue}}}{{/defaultValue}}
{{/isEnum}}
{{^isEnum}}
    {{#description}}/** {{description}} */
    {{/description}}public var {{name}}: {{{datatype}}}{{^unwrapRequired}}?{{/unwrapRequired}}{{#unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}{{#defaultValue}} = {{{defaultValue}}}{{/defaultValue}}
{{/isEnum}}
{{/vars}}

{{#additionalPropertiesType}}
    public var additionalProperties: [AnyHashable:{{{additionalPropertiesType}}}] = [:]

{{/additionalPropertiesType}}
{{^unwrapRequired}}
    {{^parent}}public override init() {}{{/parent}}{{/unwrapRequired}}
{{#unwrapRequired}}
    public init({{#allVars}}{{^-first}}, {{/-first}}{{name}}: {{#isEnum}}{{datatypeWithEnum}}{{/isEnum}}{{^isEnum}}{{datatype}}{{/isEnum}}{{^required}}?=nil{{/required}}{{/allVars}}) {
        {{#vars}}
        self.{{name}} = {{name}}
        {{/vars}}
    }{{/unwrapRequired}}

    public required init?(coder aDecoder: NSCoder){
        {{#vars}}
        {{#isEnum}}
        self.{{name}} = aDecoder.decodeObject(forKey: "{{name}}") as? {{{datatypeWithEnum}}}
        {{/isEnum}}
        {{^isEnum}}
        self.{{name}} = aDecoder.decodeObject(forKey: "{{name}}") as? {{{datatype}}}
        {{/isEnum}}
        {{/vars}}
    }
{{#additionalPropertiesType}}
    public subscript(key: AnyHashable) -> {{{additionalPropertiesType}}}? {
        get {
            if let value = additionalProperties[key] {
                return value
            }
            return nil
        }

        set {
            additionalProperties[key] = newValue
        }
    }
{{/additionalPropertiesType}}
    // MARK: JSONEncodable
    {{#parent}}override {{/parent}}open func encodeToJSON() -> Any {
        var nillableDictionary = {{#parent}}super.encodeToJSON() as? [String:Any?] ?? {{/parent}}[String:Any?](){{#vars}}{{#isNotContainer}}{{#isPrimitiveType}}{{^isEnum}}{{#isInteger}}
        nillableDictionary["{{baseName}}"] = self.{{name}}{{^unwrapRequired}}?{{/unwrapRequired}}{{#unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}.encodeToJSON(){{/isInteger}}{{#isLong}}
        nillableDictionary["{{baseName}}"] = self.{{name}}{{^unwrapRequired}}?{{/unwrapRequired}}{{#unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}.encodeToJSON(){{/isLong}}{{^isLong}}{{^isInteger}}
        nillableDictionary["{{baseName}}"] = self.{{name}}{{/isInteger}}{{/isLong}}{{/isEnum}}{{/isPrimitiveType}}{{#isEnum}}
        nillableDictionary["{{baseName}}"] = self.{{name}}{{^unwrapRequired}}?{{/unwrapRequired}}{{#unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}.rawValue{{/isEnum}}{{^isPrimitiveType}}
        nillableDictionary["{{baseName}}"] = self.{{name}}{{^unwrapRequired}}?{{/unwrapRequired}}{{#unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}.encodeToJSON(){{/isPrimitiveType}}{{/isNotContainer}}{{#isContainer}}{{^isEnum}}
        nillableDictionary["{{baseName}}"] = self.{{name}}{{^unwrapRequired}}?{{/unwrapRequired}}{{#unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}.encodeToJSON(){{/isEnum}}{{#isEnum}}{{#isListContainer}}
        nillableDictionary["{{baseName}}"] = self.{{name}}{{^unwrapRequired}}?{{/unwrapRequired}}{{#unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}.map({$0.rawValue}).encodeToJSON(){{/isListContainer}}{{#isMapContainer}}//TODO: handle enum map scenario{{/isMapContainer}}{{/isEnum}}{{/isContainer}}{{/vars}}

        {{#additionalPropertiesType}}
        for (key, value) in additionalProperties {
            if let key = key as? String {
               nillableDictionary[key] = value
            }
        }

        {{/additionalPropertiesType}}
        let dictionary: [String:Any] = APIHelper.rejectNil(nillableDictionary) ?? [:]
        return dictionary
    }

    public func encode(with aCoder: NSCoder) {
        {{#vars}}
        aCoder.encode({{name}}, forKey: "{{name}}")
        {{/vars}}
    }
}
{{/vars.isEmpty}}
{{/isEnum}}
{{/isArrayModel}}
{{/model}}
{{/models}}

在上面的代码中，只需要一个循环。

Answer 3

首先，代码中存在一些错误：

get()

正如其他答案所说的那样：一个循环很有用但是调用foreach 2次的费用大于1，所以你可以在那里使用for (String button : buttonresourceIds2) { if (buttonresourceIds.contains(button)) { System.out.println("Exist : " + button); elementInCommon++; } else { System.out.println("Not Exist : " + button); } }功能：

buttonresourceIds.retainAll(buttonresourceIds2);
int elementInCommom = buttonresourceIds.size();

之后你想要计算共同的元素，所以你要添加一个变量，如果包含

，它会自行递增

更简单的方法<2> 将是：

public void generate(View view) {
        Random rand = new Random();
        int number =  rand.nextInt(69)+1;

        TextView myText = (TextView)findViewById(R.id.textView);
        String myString = String.valueOf(number);
        myText.setText(myString);
    }

Answer 4

public static void main(String[] args) {
        ArrayList<String> buttonresourceIds = new ArrayList<String>();
        ArrayList<String> buttonresourceIds2 = new ArrayList<String>();
        buttonresourceIds.add("1");
        buttonresourceIds.add("2");
        buttonresourceIds.add("3");

        buttonresourceIds2.add("1");
        buttonresourceIds2.add("2");
        buttonresourceIds2.add("4");


            for(int i=0;i<buttonresourceIds.size();i++){

                for(int j=i;j<buttonresourceIds2.size();j++){
                if(buttonresourceIds.contains(buttonresourceIds2.get(j))){
                    System.out.println("Exist : "+buttonresourceIds2.get(j));
                }else{
                    System.out.println("Not Exist : "+buttonresourceIds2.get(j));
                }
                break;
            }
            }
    }

如何使用java比较两个arraylist元素

4 个答案: