c怎么是空???
var a=[1,2,3,4];
var b=[1,2,5,6];
var c;
Array.prototype.filter=function(fn, bind){
var results = [];
for (var i = 0, l = this.length; i < l; i++){
if (fn.call(bind, this[i], i, this)) results.push(this[i]);
}
return results;
}
Array.prototype.each= function(fn, bind){
for (var i = 0, l = this.length; i < l; i++) fn.call(bind, this[i], i, this);
}
c=a.filter(function(item){
b.each(function(item2){
if (item == item2)
return true;
})
})
console.log(a,b,c)
var a=[1,2,3,4];
var b=[1,2,5,6];
var c;
Array.prototype.filter=function(fn, bind){
var results = [];
for (var i = 0, l = this.length; i < l; i++){
if (fn.call(bind, this[i], i, this)) results.push(this[i]);
}
return results;
}
Array.prototype.each= function(fn, bind){
for (var i = 0, l = this.length; i < l; i++) fn.call(bind, this[i], i, this);
}
c=a.filter(function(item){
b.each(function(item2){
if (item == item2)
return true;
})
})
console.log(a,b,c)
var a=[1,2,3,4];
var b=[1,2,5,6];
var c;
Array.prototype.filter=function(fn, bind){
var results = [];
for (var i = 0, l = this.length; i < l; i++){
if (fn.call(bind, this[i], i, this)) results.push(this[i]);
}
return results;
}
Array.prototype.each= function(fn, bind){
for (var i = 0, l = this.length; i < l; i++) fn.call(bind, this[i], i, this);
}
c=a.filter(function(item){
//b.each(function(item2){
for(var i=0;i<4;i++)
if (item == b[i])
return true;
//})
})
var b=[1,2,5,6];
var c;
Array.prototype.filter=function(fn, bind){
var results = [];
for (var i = 0, l = this.length; i < l; i++){
//判断的是fn的return值,联系下面的注释
if (fn.call(bind, this[i], i, this)) results.push(this[i]);
}
return results;
}
Array.prototype.each= function(fn, bind){
for (var i = 0, l = this.length; i < l; i++) fn.call(bind, this[i], i, this);
}
c=a.filter(function(item){
var re = false;
b.each(function(item2){
if (item == item2)
//return true;//在这里return有啥用?这个域并非filter的callback函数的域
re = true;
})
return re;//在这里return才有用
})
alert(c);