JS中彻底删除JSON对象组成的数组中的元素

在 JS 中对于某个由 JSON 对象组成的数组例如var test [{ a: 1, b: 2 }, { a: 3, b: 4 }, { a: 5, b: 6 }];如果我们想要删除其中的第二个json对象应该怎么做呢其实方法和操作数组完全相同。在最开始的时候尝试使用了 delete 运算符但在查询数组长度的时候发现其实这种方法并不是彻底删除元素而是删除它的值但仍会保留空间。1234vartest [{a:1,b:2}, {a:3,b:4}, {a:5,b:6}];test.length//输出为 3deletetest[1];test.length//输出仍为 3查询运算符 delete 我们知道它只是将该值置为 undefined而不会影响数组长度即将其变为稀疏数组《JS权威指南》7.5节。了解及此也许想着可以将删除点之后的元素各往前移动1个单位实现彻底剔除该元素但在JS方法中我们可以查到一种更加简便的方式splice() 方法1234vartest [{a:1,b:2}, {a:3,b:4}, {a:5,b:6}];test.length//输出为 3test.splice(1, 1);test.length//输出为 2删除后 test.length 变为 2这正是我们想要的结果。JavaScript splice() 方法数组中添加新元素123456789101112131415161718192021!DOCTYPE htmlhtmlheadmeta charsetutf-8titlejs数组添加元素_脚本之家/title/headbodyp iddemo点击按钮向数组添加元素。/pbutton onclickmyFunction()点我/buttonscriptfunctionmyFunction(){varfruits [Banana,Orange,Apple,Mango];fruits.splice(2,0,Lemon,Kiwi);varxdocument.getElementById(demo);x.innerHTMLfruits;}/script/body/htmlsplice定义和用法splice() 方法用于添加或删除数组中的元素。注意这种方法会改变原始数组。返回值如果仅删除一个元素则返回一个元素的数组。 如果未删除任何元素则返回空数组。语法array.splice(index,howmany,item1,.....,itemX)参数 Values参数描述index必需。规定从何处添加/删除元素。该参数是开始插入和或删除的数组元素的下标必须是数字。howmany可选。规定应该删除多少元素。必须是数字但可以是 0。如果未规定此参数则删除从 index 开始到原数组结尾的所有元素。item1, ..., itemX可选。要添加到数组的新元素返回值Type描述Array如果从 arrayObject 中删除了元素则返回的是含有被删除的元素的数组。更多实例实例移除数组的第三个元素并在数组第三个位置添加新元素:123456789101112131415161718192021!DOCTYPE htmlhtmlheadmeta charsetutf-8title脚本之家/title/headbodyp iddemo点击按钮添加和删除元素。/pbutton onclickmyFunction()点我/buttonscriptfunctionmyFunction(){varfruits [Banana,Orange,Apple,Mango];fruits.splice(2,1,Lemon,Kiwi);varxdocument.getElementById(demo);x.innerHTMLfruits;}/script/body/html实例从第三个位置开始删除数组后的两个元素123456789101112131415161718192021!DOCTYPE htmlhtmlheadmeta charsetutf-8title脚本之家/title/headbodyp iddemo点击按钮删除数组中的两个元素。/pbutton onclickmyFunction()点我/buttonscriptfunctionmyFunction(){varfruits [Banana,Orange,Apple,Mango];fruits.splice(2,2);varxdocument.getElementById(demo);x.innerHTMLfruits;}/script/body/html到此这篇关于JS中彻底删除JSON对象组成的数组中的元素的文章就介绍到这了\my.oschina.net/u/3427593/blog/19549979my.oschina.net/u/3794224/blog/19549970my.oschina.net/u/3427593/blog/19549964my.oschina.net/u/3794224/blog/19549955my.oschina.net/u/3427593/blog/19549951my.oschina.net/u/3794224/blog/19549940my.oschina.net/u/3427593/blog/19549936my.oschina.net/u/3794224/blog/19549927my.oschina.net/u/3427593/blog/19549922my.oschina.net/u/3427593/blog/19549909my.oschina.net/u/3794224/blog/19549894my.oschina.net/u/3427593/blog/19549892my.oschina.net/u/3794224/blog/19549879my.oschina.net/u/3427593/blog/19549878my.oschina.net/u/3427593/blog/19549865my.oschina.net/u/3794224/blog/19549864my.oschina.net/u/3427593/blog/19549851my.oschina.net/u/3794224/blog/19549852my.oschina.net/u/3427593/blog/19549836my.oschina.net/u/3794224/blog/19549835my.oschina.net/u/3427593/blog/19549824my.oschina.net/u/3794224/blog/19549823my.oschina.net/u/3794224/blog/19549808my.oschina.net/u/3427593/blog/19549807my.oschina.net/u/3427593/blog/19549794my.oschina.net/u/3794224/blog/19549793my.oschina.net/u/3427593/blog/19549780my.oschina.net/u/3794224/blog/19549779my.oschina.net/u/3794224/blog/19549766my.oschina.net/u/3427593/blog/19549765my.oschina.net/u/3794224/blog/19549752my.oschina.net/u/3427593/blog/19549751my.oschina.net/u/3794224/blog/19549736my.oschina.net/u/3427593/blog/19549735my.oschina.net/u/3427593/blog/19549724my.oschina.net/u/3794224/blog/19549723my.oschina.net/u/3794224/blog/19549712my.oschina.net/u/3427593/blog/19549711my.oschina.net/u/3794224/blog/19549696my.oschina.net/u/3427593/blog/19549695my.oschina.net/u/3794224/blog/19549681my.oschina.net/u/3427593/blog/19549680my.oschina.net/u/3794224/blog/19549667my.oschina.net/u/3427593/blog/19549666my.oschina.net/u/3794224/blog/19549652my.oschina.net/u/3427593/blog/19549651my.oschina.net/u/3427593/blog/19549641my.oschina.net/u/3794224/blog/19549640my.oschina.net/u/3794224/blog/19549624my.oschina.net/u/3427593/blog/19549623my.oschina.net/u/3427593/blog/19549610my.oschina.net/u/3794224/blog/19549609my.oschina.net/u/3794224/blog/19549594my.oschina.net/u/3427593/blog/19549593my.oschina.net/u/3794224/blog/19549578my.oschina.net/u/3427593/blog/19549577my.oschina.net/u/3794224/blog/19549568my.oschina.net/u/3427593/blog/19549567my.oschina.net/u/3427593/blog/19549551my.oschina.net/u/3794224/blog/19549550my.oschina.net/u/3794224/blog/19549536my.oschina.net/u/3427593/blog/19549537my.oschina.net/u/3794224/blog/19549524my.oschina.net/u/3427593/blog/19549523my.oschina.net/u/3427593/blog/19549507my.oschina.net/u/3794224/blog/19549506my.oschina.net/u/3427593/blog/19549493my.oschina.net/u/3794224/blog/19549492my.oschina.net/u/3427593/blog/19549480my.oschina.net/u/3794224/blog/19549479my.oschina.net/u/3427593/blog/19549466my.oschina.net/u/3794224/blog/19549465my.oschina.net/u/3794224/blog/19549453my.oschina.net/u/3427593/blog/19549452my.oschina.net/u/3427593/blog/19549437my.oschina.net/u/3794224/blog/19549436my.oschina.net/u/3427593/blog/19549422my.oschina.net/u/3794224/blog/19549421my.oschina.net/u/3427593/blog/19549407my.oschina.net/u/3794224/blog/19549406my.oschina.net/u/3427593/blog/19549394my.oschina.net/u/3794224/blog/19549395my.oschina.net/u/3427593/blog/19549382my.oschina.net/u/3794224/blog/19549381my.oschina.net/u/3427593/blog/19549367my.oschina.net/u/3794224/blog/19549366my.oschina.net/u/3794224/blog/19549354my.oschina.net/u/3427593/blog/19549353my.oschina.net/u/3794224/blog/19549338my.oschina.net/u/3427593/blog/19549337my.oschina.net/u/3794224/blog/19549325my.oschina.net/u/3427593/blog/19549324my.oschina.net/u/3427593/blog/19549310my.oschina.net/u/3794224/blog/19549309my.oschina.net/u/3794224/blog/19549294my.oschina.net/u/3427593/blog/19549293my.oschina.net/u/3427593/blog/19549281my.oschina.net/u/3794224/blog/19549280my.oschina.net/u/3427593/blog/19549267my.oschina.net/u/3794224/blog/19549264my.oschina.net/u/3427593/blog/19549251my.oschina.net/u/3794224/blog/19549250my.oschina.net/u/3794224/blog/19549236my.oschina.net/u/3427593/blog/19549235my.oschina.net/u/3427593/blog/19549225my.oschina.net/u/3794224/blog/19549224my.oschina.net/u/3794224/blog/19549210my.oschina.net/u/3427593/blog/19549209my.oschina.net/u/3794224/blog/19549197my.oschina.net/u/3427593/blog/19549196my.oschina.net/u/3427593/blog/19549181my.oschina.net/u/3794224/blog/19549180my.oschina.net/u/3427593/blog/19549165my.oschina.net/u/3794224/blog/19549164my.oschina.net/u/3794224/blog/19549153my.oschina.net/u/3427593/blog/19549154my.oschina.net/u/3794224/blog/19549140my.oschina.net/u/3427593/blog/19549139my.oschina.net/u/3794224/blog/19549127my.oschina.net/u/3427593/blog/19549126my.oschina.net/u/3794224/blog/19549110my.oschina.net/u/3427593/blog/19549109my.oschina.net/u/3794224/blog/19549096my.oschina.net/u/3427593/blog/19549095my.oschina.net/u/3794224/blog/19549081my.oschina.net/u/3427593/blog/19549080my.oschina.net/u/3794224/blog/19549070my.oschina.net/u/34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