if(i==j){if(j==k)console.log("i equals k");elseconsole.log("i doesn't equal j");//错误!} 和大多数编程语言一样,JavaScript中的if、else匹配规则是,else总是和就近的if语句匹配。为了让这个例子可读性更强、更易理解、更方便维护和调试,应当适当地使用花括号: if(i==j){if(j==k){console...
在 ES2020 之前,如果你想编写一个像sort()这样的方法,它接受一个可选的函数参数,你通常会使用一个if语句来检查函数参数在if体中调用之前是否已定义: 代码语言:javascript 复制 function square(x, log) { // The second argument is an optional function if (log) { // If the optional function is passe...
function createFile(name, temp) { if (temp) { fs.create('./temp/' + name); } else { fs.create(name); } } 正例: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 function createTempFile(name) { fs.create('./temp/' + name); } --- function createFile(name) { fs.create(name...
句号 middle dot: ・ 中间点 interpunct: · 间隔号 hyphenation point: · 连字点 solidus: / 斜线 colon: : 冒号 semicolon: ; 分号 less-than sign: < 小于符号 equals sign: = 等于符号 greater-than sign: > 大于符号 question mark: ? 问号 low line: _ 下划线 digital 0: 0 数字 0 latin ...
functionsquare(x, log) {// The second argument is an optional functionlog?.(x);// Call the function if there is onereturnx * x;// Return the square of the argument} 但请注意,?.()仅检查左侧是否为null或undefined。它不验证该值实际上是否为函数。因此,在这个例子中,如果你向square()函数传...
Here's the syntax of an if statement: if (expression) statement; We start with the if keyword, followed by a pair of parentheses (()). Inside these parentheses, we put an expression that is the condition to evaluate. If this condition evaluates to the Boolean value true, the following ...
// Block used as part of a conditional statementif (isLie(cake)) {triumph = true;makeNote('huge success');satisfaction += 10;}// Block used as part of a function declarationfunction makeNote(message) {note = message;}}();正如您之前看到的,函数本质上是开发人员可以按需调用的命名块。这...
For example, an if statement cannot become the argument of a function. 一般来说,语句的作用是执行一个动作,例如循环遍历和条件语句。一段程序基本上是由一连串的语句组成(这里,我们先忽略声明语句)。在 JavaScript 中,任何一个能够出现语句的地方,都可以用表达式代替。这样的语句被称为 表达式语句。但是,反过来...
In this case,27 % 2equals to1. Hence, the number is odd. The above program can also be written using a ternary operator. Example 2: Using Ternary Operator // program to check if the number is even or odd// take input from the userconstnumber = prompt("Enter a number: ");// ter...
In essence, an if statement simply executes some code if a value is equivalent to true. The if statement syntax if(true){alert('Yay!');} Let’s have a look at what’s going on here. In essence, we’re simply sayingif the stuff inside the brackets is equivalent to true, execute th...