someWonderfulHtml = '' + getEvenMoreHtml(someReallyInterestingValues, moreValues, evenMoreParams, 'a duck', true, 72, slightlyMoreMonkeys(0xfff)) + ''; thisIsAVeryLongVariableName = hereIsAnEvenLongerOtherFunctionNameThatWillNotFitOnPrevLine(); thisIsAVeryLongVariableName = 'expressionPartOne'...
全局范围:在全局命名空间中声明的变量或函数驻留在全局范围内,使它们可以从代码中的任何位置访问。 //global namespacevarg ="global"; functionglobalFunc(){functioninnerFunc(){console.log(g);// can access "g" because "g" is a global variable}innerFunc(...
// Two slashes start single-line commentsvarx;// declaring a variablex=3+y;// assigning a value to the variable `x`foo(x,y);// calling function `foo` with parameters `x` and `y`obj.bar(3);// calling method `bar` of object `obj`// A conditional statementif(x===0){// Is ...
//typeof操作符的操作数可以是变量(message)、也可以是数值字面量,操作符返回下列字符串"undefined":这个值未定义"boolean":布尔值"string":字符串"number":数值"object":对象或null"function":函数 eg:varmessage="some string"; alert(typeofmessage);//"string"alert(typeof(message));//"string"alert(typ...
varmap;//Global variablerequire(["esri/map"],function(Map) { map =newMap("myMap", {basemap:"national-geographic"}); }); }); 这意味着我们可以在浏览器控制台中访问地图的属性。在缩放地图和所需的范围作为地图初始范围之后,使用Ctrl+Shift+I命令(在 Chrome 中)打开开发者工具。在 JavaScript ...
> var foo = 'hello'; > this.foo // read global variable 'hello' > this.bar = 'world'; // create global variable > bar 'world' 请注意,全局对象具有原型。如果你想列出它的(自己的和继承的)所有属性,你需要一个诸如getAllPropertyNames()的函数,来自[列出所有属性键](ch17_split_000.html#get...
Backticks are generally used when you need to insert variables or expressions into a string. This is done by wrapping variables or expressions with${variable or expression}. For example, // strings exampleletname1 ='Peter';letname2 ="Jack";letresult =`The names are${name1}and${name2}`...
If you put a number in quotes, it will be treated as a text string. Example constpi =3.14; letperson ="John Doe"; letanswer ='Yes I am!'; Try it Yourself » Declaring a JavaScript Variable Creating a variable in JavaScript is called "declaring" a variable. ...
(); // => ReferenceError superPower is not defined var named = function superPower() { console.log('Flying'); };}// the same is true when the function name// is the same as the variable name.function example() { console.log(named); // => undefined named(); // => TypeError ...
All string methods return a new value. They do not change the original variable. String HTML Wrapper Methods HTML wrapper methods return a string wrapped inside an HTML tag. These are not standard methods, and may not work as expected. ...