JS数组操作(数组增加、删除、翻转、转字符串、取索引、截取(切片)slice、剪接splice、数组合并)
POP删除最后一项
删除最后一项,并返回删除元素的值；如果数组为空则返回undefine
vara=[1,2,3,4,5]; a.pop();//a：[1,2,3,4] a.pop();//a：[1,2,3] a.pop();//a：[1,2]
shift删除第一项
删除原数组第一项，并返回删除元素的值；如果数组为空则返回undefine
vara=[1,2,3,4,5]; a.shift();//a：[2,3,4,5] a.shift();//a：[3,4,5]
push增加到最后
并返回新数组长度；
vara=[1,2,3,4,5];
a.push(6);//[1,2,3,4,5,6]
aa.push('xx');//[1,2,3,4,5,6,"xx"]返回长度7
a.push('yy');//[1,2,3,4,5,6,"xx","yy"]返回长度8
unshift增加到最前
并返回新数组长度；
vara=[1,2,3,4,5];
a.unshift();//[1,2,3,4,5]
a.unshift("cc");//["cc",1,2,3,4,5]返回长度6
a.unshift("aaa");//["aaa","cc",1,2,3,4,5]返回长度7
reverse数组翻转
并返回翻转后的原数组，原数组翻转了
vara=[1,2,3,4,5]; a.reverse()//a：[5,4,3,2,1]返回[5,4,3,2,1]
join数组转成字符串
并返回字符串，原数组木变
vara=[1,2,3,4,5];
varb=a.join('||');//b:"1||2||3||4||5"a:[1,2,3,4,5]
indexOf数组元素索引
并返回元素索引，不存在返回-1,索引从0开始
vara=['a','b','c','d','e'];
a.indexOf('a');//0
a.indexOf(a);//-1
a.indexOf('f');//-1
a.indexOf('e');//4
slice截取(切片)数组得到截取的数组
返回从原数组中指定开始索引(包含)到结束索引(不包含)之间的项组成的新数组,原数组木变，索引从0开始
vara=['a','b','c','d','e']; a.slice(1,3);//["b","c"]a:['a','b','c','d','e'] a.slice(0,4);//["a","b","c","d"] a.slice(3,4);//["d"]
splice剪接数组原数组变化可以实现shift前删除，pop后删除,unshift前增加,同push后增加一样的效果
返回剪接的元素数组,原数组变化，索引从0开始
/*参数是2个*/ //第一参数是索引（从0开始），第二是长度 vara=['a','b','c','d','e']; a.splice(0,2);//["a","b"]a:["c","d","e"] a.splice(0,2);//["c","d"]a:["e"] vara=['a','b','c','d','e']; a.splice(0,1);//["a"]a:["b","c","d","e"]同shift前删除 vara=['a','b','c','d','e'] a.splice(a.length-1,1)l//["e"]a:["a","b","c","d"]同pop前删除 /*参数大于2个*/ //splice(start,deleteCount,val1,val2,...)：从start位置开始删除deleteCount项，并从该位置起插入val1,val2,... vara=['a','b','c','d','e']; a.splice(3,1,10,21,238,99);//["d"]a:["a","b","c",10,21,238,99,"e"] vara=['a','b','c','d','e']; a.splice(a.length,100000000,88)//返回[]从最后元素后面的元素，截取长度任意个，肯定是空a：["a","b","c","d","e",88]同push后增加 vara=['a','b','c','d','e']; a.splice(a.length,0,88)//返回[]从最后元素后面的元素，截取长度任意个，肯定是空a：["a","b","c","d","e",88]同push后增加 vara=['a','b','c','d','e']; a.splice(0,0,88,99)//返回[]从第一个元素，截取长度0个肯定是空a:[88,99,"a","b","c","d","e"]同unshift前增加
concat数组合并
返回合并后的新数组,原数组木变
vara=['a','b','c','d','e']; a.concat([88,99]);//["a","b","c","d","e",88,99]a:["a","b","c","d","e"] varb=[9999,10000] a.concat(b);//["a","b","c","d","e",9999,10000]a:["a","b","c","d","e"]
以上所述是小编给大家介绍的JS数组操作(数组增加、删除、翻转、转字符串、取索引、截取(切片)slice、剪接splice、数组合并)，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对毛票票网站的支持！