Reference
网页的动作语言
Examples are better than 1000 words.——一例胜千言
<head></head>
<body></body>
<script></script>
<script type="text/javascript" src="javascript.js"></script>
- innerHTML
document.getElementById("demo").innerHTML='Hello World!';
- document.write()
- window.alert()
- console.log()
- print()
- getElementById("demo")
- getElementsByClassName("demo")
- getElementsByTagName("p")
- querySelectorAll("p.intro")
- var
- let
- cost
- //单行注释
- /*多行注释*/
- +
- -
- *
- **
- /
- %
- ++
- --
- &&
- ||
- !
- ==
- ===
- !=
- !==
- >
- <
- >=
- <=
- ?
- +=
- -=
- *=
- /=
- %=
- **=
function myFunction(p1, p2) {
return p1 * p2; // The function returns the product of p1 and p2
}
- 数组:x = ["a","b","c"]
- 物体:x={name:"fiat",model:"modern",color:"white"}
- .length
- indexOf()
- lastIndexOf()
- search()
- slice()
- substring()
- substr()
- replace()
- toUpperCase()
- toLowerCase()
- concat()
- trim()
- charAt()
- charCodeAt()
- split()
Js语法中,支持数位是15位,以及小数点后17位。
NaN = not a number
isNaN()
数字进制
var myNumber = 32;
myNumber.toString(10); // returns 32
myNumber.toString(32); // returns 10
myNumber.toString(16); // returns 20
myNumber.toString(8); // returns 40
myNumber.toString(2); // returns 100000
数字变成物体
var x = new Number(124);
- toExponential()
- toFixed()
- toPrecision()
var cars = ["Saab", "Volvo", "BMW"];||var cars = new Array("Saab", "Volvo", "BMW");
- array.foreach()
- array.push()
- array.pop()
- typeof.array
- array.join("*")
- array.shift()
- array.unshift()
- delete array[0]
- array.splice(2,0,"apple","orange")
- array.concat(array)
- sort()
- reverse()
调用
person.lastName;||person["lastName"];
- Date(year, month, day, hours, minutes, seconds, milliseconds)
- toUTCString()
- toISOString()
- toDateString()
getFullYear() | Get the year as a four digit number (yyyy) |
getMonth() | Get the month as a number (0-11) |
getDate() | Get the day as a number (1-31) |
getHours() | Get the hour (0-23) |
getMinutes() | Get the minute (0-59) |
getSeconds() | Get the second (0-59) |
getMilliseconds() | Get the millisecond (0-999) |
getTime() | Get the time (milliseconds since January 1, 1970) |
getDay() | Get the weekday as a number (0-6) |
Date.now() | Get the time. ECMAScript 5. |
Method | Description |
getUTCDate() | Same as getDate(), but returns the UTC date |
getUTCDay() | Same as getDay(), but returns the UTC day |
getUTCFullYear() | Same as getFullYear(), but returns the UTC year |
getUTCHours() | Same as getHours(), but returns the UTC hour |
getUTCMilliseconds() | Same as getMilliseconds(), but returns the UTC milliseconds |
getUTCMinutes() | Same as getMinutes(), but returns the UTC minutes |
getUTCMonth() | Same as getMonth(), but returns the UTC month |
getUTCSeconds() | Same as getSeconds(), but returns the UTC seconds |
Method | Description |
setDate() | Set the day as a number (1-31) |
setFullYear() | Set the year (optionally month and day) |
setHours() | Set the hour (0-23) |
setMilliseconds() | Set the milliseconds (0-999) |
setMinutes() | Set the minutes (0-59) |
setMonth() | Set the month (0-11) |
setSeconds() | Set the seconds (0-59) |
setTime() | Set the time (milliseconds since January 1, 1970) |
- Math.PI
- Math.round()
- Math.pow()
- Math.sqrt()
- Math.abs()
- Math.ceil()
- Math.floor()
- Math.sin()
- Math.cos()
- Math.min()
- Math.max()
- Math.random()
- Math.E
- Math.SQRT2
- Math.SQRT1_2
- Math.LN2
- Math.LN10
- Math.LOG2E
- Math.LOG10E
True or False
if (condition) {
// block of code to be executed if the condition is true
} else {
// block of code to be executed if the condition is false
}
- Boolean()
- variablename = (condition) ? value1:value2
if (condition1) {
// block of code to be executed if condition1 is true
} else if (condition2) {
// block of code to be executed if the condition1 is false and condition2 is true
} else {
// block of code to be executed if the condition1 is false and condition2 is false
}
switch(expression) {
case x:
// code block
break;
case y:
// code block
break;
default:
// code block
}
switch (new Date().getDay()) {
case 6:
text = "Today is Saturday";
break;
case 0:
text = "Today is Sunday";
break;
default:
text = "Looking forward to the Weekend";
}
Last modified 3yr ago