function up(x,y){//升序
return x[val.prop] - y[val.prop]
}
function down(x,y){//降序
return y[val.prop] - x[val.prop]
}
arr.sort(up)
arr.sort(down)
function up(x,y){//升序
return x[val.prop] - y[val.prop]
}
function down(x,y){//降序
return y[val.prop] - x[val.prop]
}
arr.sort(up)
arr.sort(down)