但是这个argument无法获得this。 i就是你参数的位置 第一个为0 所以要设定 flag 的默认值 则可以这么写 function func(string1,url,flag,icon){ if(!arguments[2]) flag = "123"; if(!arguments[3]) icon = "456"; } 1. 2. 3. 4. 你试试 应该是这样 今天遇到一个问题,需要调用一个JS函数,想在...
Only one argument If your function only takes one parameter, you can omit the parentheses around it. If we take back the above double code:const double = (x) => x * 2; // this arrow function only takes one parameterParentheses around the parameter can be avoided:...
const double = (x) => x * 2; // this arrow function only takes one parameterParentheses around the parameter can be avoided:const double = x => x * 2; // this arrow function only takes one parameterNo arguments When there is no argument provided to an arrow function, you need to ...
y) 3 } 4 test1(10)//10 1 2.rest参数：形式为...变量名 1 function test2(a,...b)...
// eg1.jsconst { Command } = require('commander');const program = new Command();program.name('字符串工具').description('一些JavaScript字符串实用程序的 命令行工具').version('0.0.1');program.command('split').description('将字符串拆分成子字符串,并显示为数组').argument('<string>', '要拆...
bool = document.execCommand(aCommandName, aShowDefaultUI, aValueArgument) 1. 返回值 一个Boolean类型,如果是false则表示操作不被支持或未被启用。 2. 参数 2.1 aCommandName 一个DOMString ,命令的名称。可用命令列表请参阅 命令 。 2.2 aShowDefaultUI ...
function myParseInt(value, dummyPrevious) { // parseInt 参数为字符串和进制数 const parsedValue = parseInt(value, 10); if (isNaN(parsedValue)) { throw new commander.InvalidArgumentError('Not a number.'); } return parsedValue; } function increaseVerbosity(dummyValue, previous) { return previou...
"Jump target cannot cross function boundary.": "跳转目标不能跨越函数边界。", "A 'return' statement can only be used within a function body.": "\"return\" 语句只能在函数体中使用。", "Expression expected.": "应为表达式。", "Type expected.": "应为类型。", ...
In all examples below, semicolons andtoStringcalls are not shown. If a commented-out value is in quotes it meanstoStringhas been called on the preceding expression. The library exports a single constructor function,Decimal, which expects a single argument that is a number, string or Decimal in...
the map's style. The only required parameter foraddLayeris a Mapbox style layer object. It also accepts an optionalbeforeparameter, which is the ID of an existing layer to insert the new layer before. If you omit this argument, then the renderer will draw the layer on top of the map....