if( this.length ) { } 这句话有什么用?

if( this.length ) { } 这句话有什么用? for (var i = 0,length = this.length >>> 0; i < length; i++) 为什么要这么写 lenght>>>0?这是prototype框架里的一个函数function each(iterator,context) {for (var i = 0,length = this.length >>> 0; i < length; i++) {if (i in this) iterator. What is the length of this ruler? function makeArray(n) { this.length=n; alert(this.length); } 怎么理解啊?function makeArray(n){ this.length=n; return this; }怎么理解?希望各位指点迷津! length(x)在matlab中是什么意思?if length(h)>1 || h2*b return是什么意思? if(a[i]==a.length-1)是什么意思 This bridge is three times the length of that one.. an equilateral triangle has a side length of 20 .if a square has the same perimeter as this triangle,the area of the square is?这题怎么翻译?怎么算? 英语翻译karl's team score is 39 points.this was one point less than twice todd's team score.find todd's team score.the length of a rectangle is 6 feet more than twice the wldth.if the length is 24 feet,what is the width?four fifths of the third g if(r.length===0|www.vip400.cc|f!=null&&r.length===1)中的length有什么作用? 1.the square is divided into five rectangles ,the perimeter of each reactangle is 30 cm,if you don't set x can you work out the perimeter of this square?2.a small square 's side length is 4cm ,if we make 9 squares like this into a big square,what is If this is If this was a 关于javascript的this在代码中代表什么?为什么一个是this一个是this.form?function processData(form){ for (var i = 0; i < form.Beatles.length; i++) { if (form.Beatles[i].checked) { break; } } var beatle = form.Beatles[i].value; var son this ladder is 8 metres in length.改为同义句this is___ ___ladder 数据结构：if(L.length>=listsize)这个语句该怎么理解啊如题 if ($.trim($(#name).val()).length==0) ,$和#,还有这一句到底是什么意思? Length:Radom length