API目录
- Arguments
- Arguments.callee
- Arguments.length
- arguments[]
- Array
- Array.concat()
- Array.join()
- Array.length
- Array.pop()
- Array.push()
- Array.reverse()
- Array.shift()
- Array.slice()
- Array.sort()
- Array.splice()
- Array.toLocaleString()
- Array.toString()
- Array.unshift()
- Boolean
- Boolean.toString()
- Boolean.valueOf()
- Date
- Date.getDate()
- Date.getDay()
- Date.getFullYear()
- Date.getHours()
- Date.getMilliseconds()
- Date.getMinutes()
- Date.getMonth()
- Date.getSeconds()
- Date.getTime()
- Date.getTimezoneOffset()
- Date.getUTCDate()
- Date.getUTCDay()
- Date.getUTCFullYear()
- Date.getUTCHours()
- Date.getUTCMilliseconds()
- Date.getUTCMinutes()
- Date.getUTCMonth()
- Date.getUTCSeconds()
- Date.getYear()
- Date.parse()
- Date.setDate()
- Date.setFullYear()
- Date.setHousr()
- Date.setMilliseconds()
- Date.setMinutes()
- Date.setMonth()
- Date.setSeconds()
- Date.setTime()
- Date.setUTCDate()
- Date.setUTCFullYear()
- Date.setUTCHours()
- Date.setUTCMilliseconds()
- Date.setUTCMinutes()
- Date.setUTCMonth()
- Date.setUTCSeconds()
- Date.setUTCYear()
- Date.toDateString()
- Date.toGMTString()
- Date.toLocaleDateString()
- Date.toLocaleString()
- Date.toLocaleTimeString()
- Date.toString()
- Date.toTimeString()
- Date.toUTCString()
- Date.UTC()
- Date.valueOf()
- decodeURI()
- decodeURIComponent()
- encodeURI()
- encodeURIComponent()
- Error
- Error.message
- Error.neme
- Error.toString()
- escape()
- eval()
- EvalError
- Function
- Function.apply()
- Function.arguments[]
- Function.call()
- Function.caller
- Function.length
- Function.prototype
- Function.toString()
- getClass()
- Global
- ifFinite()
- Infinity
- isNaN()
- java
- JavaArray
- JavaClass
- JavaObject
- JavaPackage
- Math
- Math.abs()
- Math.acos()
- Math.asin()
- Math.atan()
- Math.atan2()
- Math.ceil()
- Math.cos()
- Math.E
- Math.exp()
- Math.floor()
- Math.LN10
- Math.LN2
- Math.log()
- Math.LOG10E
- Math.LOG2E
- Math.max()
- Math.min()
- Math.PI
- Math.pow()
- Math.random()
- Math.round()
- Math.sin()
- Math.sqrt()
- Math.SQRT1_2
- Math.SQRT2
- Math.tan()
- NaN
- Number
- Number.MAX_VALUE
- Number.MIN_VALUE
- Number.NaN
- Number.NEGATIVE_INFINITY
- Number.POSITIVE_INFINITY
- Number.toExponetial()
- Number.toFixed()
- Number.toLocaleString()
- Number.toPrecision()
- Number.toString()
- Number.valueOf()
- Object
- Object.constructor
- Object.hasOwnProperty()
- Object.isPrototypeOf()
- Object.propertyIsEnumberable()
- Object.toLocaleString()
- Object.toString()
- Object.valueOf()
- Packages
- parseFloat()
- parseInt()
- RangeError
- ReferenceError
- RegExp
- RegExp.exec()
- RegExp.global
- RegExp.ignoreCase
- RegExp.lastIndex
- RegExp.source
- RegExp.test()
- RegExp.toString()
- Stirng.charAt()
- String
- String.charCodeAt()
- String.concat()
- String.formCharCode()
- String.indexOf()
- String.lastIndexOf()
- String.length
- String.localeCompare()
- String.match()
- String.replace()
- String.search()
- String.slice()
- String.split()
- String.substr()
- String.substring()
- String.toLocaleLowerCase()
- String.toLocaleUpperCase()
- String.toLowerCase()
- String.toString()
- String.toUpperCase()
- String.valueOf()
- SyntaxError
- TypeError
- undefined
- unescape()
- URIError
JavaScript API
打印
Math.atan2()
ECMAScript v1
计算从X轴到一个点的角度
摘要
Math.atan2(y, x)
参考
y
指定点的Y坐标。
x
指定点的X坐标。
返回值
-π到π之间的值，是从X轴正向逆时针转到点（x, y）时经过的角度。
描述
函数Math.atan2()计算的是y/x的反正切值。参数y可以看作一个点的Y坐标，x可以看作该点的X坐标。注意这个函数的参数顺序，Y坐标在X坐标之前传递。
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