var  str = ["a", "b", "c"];
    var index = str.indexOf("a");
    if(index>-1){//大于0 代表存在，
    str.splice(index,1);//存在就删除
}
console.log(str);// ["b", "c"]

var searchinfo =[
                    { key: '999', name: 'zhangsan'},
                    { key: '111', name: 'lisi'},
                    { key: '222', name: 'wanger'},
                    { key: '333', name: 'apple'},
                    { key: '444', name: 'orange'},
    
                ]
for (var i = 0; i < searchinfo.length; i++) {
            if ((searchinfo[i].key).indexOf("999") > -1) {//判断key为999的对象是否存在，
                index = i;
                searchinfo.splice(index, 1);//存在即删除
            }
        }
console.log(searchinfo);