js数组操作

数组删除元素

   let a = ['222','333'];
   let index = a.indexOf('333');
   if(index!=-1)
   a.splice(index,1);

结果：["222"]

数组添加

    let a= [];
    a.push('test');

结果：["test"]

数组filter

let a = ['test','test1','test3'];
a.filter((item) = >{
    return item!='test1'
})

结果：["test", "test3"]

数组合并

let a = ['test','test3'],b = ['test2'];
a.concat(b);

结果：["test", "test3", "test2"]

数组slice

let a = ["test", "test2", "test3", "test4"];
    a.slice(2);
    a.slice(0,-1);

结果1：[ "test3", "test4"] 结果2：["test", "test2", "test3"]