87,901
社区成员
发帖
与我相关
我的任务
分享
<script>
function b() {
Number.prototype.toString = function() { alert("xiaod") };
var ss = { toString: function() { alert("xiaoc"); } }; var f = 33; alert(f); alert(ss); }
window.onload = b;
</script>
<script>
String.prototype.toString = function(){
return 'toString~~';
}
Number.prototype.toString = function(){
return 'toString~~';
}
var s = new String('4564646464');
var b = 'sfdf';
var s1 = new Number(111111);
var b1 = 111111;
alert(s);
alert(b);
alert(s1);
alert(b1);
</script>
Number.prototype.toString = function(){
return 'toString';
}
String.prototype.toString = function(){
return 'toString';
}
Boolean.prototype.toString = function(){
return 'toString';
}
var n1 = 1;
alert(n1); //原始类型,没有调用toString
alert(n1.toString()); //如果调用toString的话
var n2 = new Number(1);
alert(n2); //引用类型,调用toString
var s1 = 'test';
alert(s1); //原始类型,没有调用toString
alert(s1.toString()); //如果调用toString的话
var s2 = new String('test');
alert(s2); //引用类型,调用toString
var b1 = true;
alert(b1); //原始类型,没有调用toString
alert(b1.toString()); //如果调用toString的话
var b2 = new Boolean('true');
alert(b2); //引用类型,调用toString
Number.prototype.toString = function(){
return 'toString';
}
String.prototype.toString = function(){
return 'toString';
}
Boolean.prototype.toString = function(){
return 'toString';
}
var n1 = 1;
alert(n1); //原始类型,没有调用toString
var n2 = new Number(1);
alert(n2); //引用类型,调用toString
var s1 = 'test';
alert(s1); //原始类型,没有调用toString
var s2 = new String('test');
alert(s2); //引用类型,调用toString
var b1 = true;
alert(b1); //原始类型,没有调用toString
var b2 = new Boolean('true');
alert(b2); //引用类型,调用toString
function b() {
Number.prototype.toString = function() { alert("xiaod") };
var ss = { toString: function() { alert("xiaoc"); } };
var n = new Number(11);
var f = 11;
alert(typeof n); //输出object
alert(typeof f); //输出number
alert(n instanceof Object); //true, n是引用类型
alert(f instanceof Object); //false, f是number的原始类型
alert(n); //先调用toString, 输出xiaod , toString没有返回值,再输出undefined
alert(f); //没有调用toString, 直接输出11
}
window.onload = b;
<script>
function b(){
Number.prototype.toString = function() { alert("xiaod"); return this.valueOf() };
var ss = { toString: function() { alert("xiaoc"); return this.valueOf() } };
var f = new Number(33);
alert(f);
alert(ss);
}
window.onload = b;
</script>
<script>
function b() {
Number.prototype.toString = function() { alert("xiaod") };
var ss = { toString: function() { alert("xiaoc"); } };
var f = 33;
alert(f);
var n = new Number();
alert(n);
alert(ss);
}
window.onload = b;
</script>