Array.push() 如果不存在? [英] Array.push() if does not exist?

问题描述

如果两个值都不存在，我如何推入数组?这是我的数组:

<预><代码>[{名称:汤姆"，文字:美味"}，{名称:汤姆"，文字:美味"}，{名称:汤姆"，文字:美味"}，{名称:汤姆"，文字:美味"}，{名称:汤姆"，文字:美味"}]

如果我尝试使用 name: "tom" 或 text: "tasty" 再次推入数组，我不希望任何事情发生... 但如果这些都不存在，那么我希望它 .push()

我该怎么做?

解决方案

您可以使用自定义方法扩展 Array 原型:

//使用比较器函数检查数组中是否存在元素//比较器:函数(currentElement)Array.prototype.inArray = 函数(比较器){for(var i=0; i < this.length; i++) {if(comparer(this[i])) 返回真；}返回假；};//如果数组不存在，则使用比较器将其添加到数组中//功能Array.prototype.pushIfNotExist = 函数(元素，比较器){如果(！this.inArray(比较器)){this.push(元素);}};var array = [{ name: "tom", text: "tasty" }];var element = { name: "tom", text: "tasty" };array.pushIfNotExist(元素，函数(e){返回 e.name === element.name &&e.text === element.text;});

How can I push into an array if neither values exist? Here is my array:

[
    { name: "tom", text: "tasty" },
    { name: "tom", text: "tasty" },
    { name: "tom", text: "tasty" },
    { name: "tom", text: "tasty" },
    { name: "tom", text: "tasty" }
]

If I tried to push again into the array with either name: "tom" or text: "tasty", I don't want anything to happen... but if neither of those are there then I want it to .push()

How can I do this?

解决方案

You could extend the Array prototype with a custom method:

// check if an element exists in array using a comparer function
// comparer : function(currentElement)
Array.prototype.inArray = function(comparer) { 
    for(var i=0; i < this.length; i++) { 
        if(comparer(this[i])) return true; 
    }
    return false; 
}; 

// adds an element to the array if it does not already exist using a comparer 
// function
Array.prototype.pushIfNotExist = function(element, comparer) { 
    if (!this.inArray(comparer)) {
        this.push(element);
    }
}; 

var array = [{ name: "tom", text: "tasty" }];
var element = { name: "tom", text: "tasty" };
array.pushIfNotExist(element, function(e) { 
    return e.name === element.name && e.text === element.text; 
});

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