內容上下會有些銜接。。。
swich迴圈語句
var n = 3;
switch(n)
var n = 'a';
switch(n)
var date = window.prompt('inout');
switch(date)
var i = 0;
while(1)
}
var i = 0;
var sum = 0;
for (i = 0; i < 100; i++)
}
for (var i = 0; i < 100; i++)
console.log(i);
} // continue直接開始下一次迴圈
var arr = [1,2,3,4,6,'da',"gasf",undefined];
for (var i = 0; i < arr.length; i++)
var deng =
console.log(deng.lastname);
deng.lastname = "old deng";
console.log(deng.lastname);
2.物件導向
typeof可以返回number string boolean object undefined function
var num = function(){};
console.log(typeof(num));
var num = 123;
console.log(typeof(num));
var num = 1 * "1";
console.log(typeof(num) + " : " + num);
var demo = "123";
var num = number(demo);
console.log(typeof(num) + " : " + num);
var demo = "123abc";
var num = parseint(demo);
console.log(typeof(num) + " : " + num);
var demo = "10";
var num = parseint(demo, 16); //以16為基底轉化成10進製
console.log(typeof(num) + " : " + num);
var demo = "123.33fefsd";
var num = parsefloat(demo);
console.log(typeof(num) + " : " + num);
var demo = "123.3212adsdwa";
var num = string(demo);
console.log(typeof(num) + " : " + num);
var demo = "123";
var num = boolean(demo);
console.log(typeof(num) + " : " + num);
var demo = "20";
var num = demo.tostring(8); //把demo的值轉化成8進製的數的結果
console.log(typeof(num) + " : " + num);
把二進位制10000轉化成16進製制的數
var num = 10000;
var text = parseint(num,2);
console.log(text.tostring(16));
console.log(isnan(null));
var a = "abc";
a ++;
console.log(a + " : " + typeof(a));
var a = "a" + 1;
console.log(a + " : " + typeof(a));
var a = 1 == true;
console.log(a + " : " + typeof(a));
var a = 1 === "1";
console.log(a + " : " + typeof(a));
console.log(typeof(typeof(a)));
console.log(typeof(a + ""));
alert(typeof(a));
alert(typeof(undefined));
alert(typeof(nan));
alert(typeof(null));
var a ="123abc";
alert(typeof(+a));
alert(typeof(!!a));
alert((typeof(a +""));
alert(1=="1");
alert(nan == nan);
alert(nan == undefined);
alert("11" + 11);
alert(1==="1");
alert(parselnt("123abc")) ;
var num = 123123.345789;
alert(num.tofixed(3));
typeof 型別轉換
parseint 作用 取整 進製轉換 以所寫引數為基地 將數字轉換為十進位制數字 parsefloat 擷取字串中的浮點數字 數字進製間轉換 paeseint demo,2 10 tostring n 將十進位制轉化為目標進製 var n parseint window.prompt input ...
typeof用法以及顯示型別轉換
返回值有number string boolean object undefined functuion 引用值會返回object null 也會返回object undefined 會返回undefined function會返回function number 轉換為number型別 null轉換...
typeof，型別轉化
對於之前的一些基礎的知識，之後會進行一些補充說明，現在要寫的是之後一些需要記住的，比較雜碎，比較重要的知識。案例描述 當周一到周五的時候，輸出working 週六日的時候，輸出relaxingvar n window.prompt 請輸入日期 switch n 案例描述 輸出1到100之間的尾數是7...