代码语言:javascript 复制 if(condition1&&condition2){// 当条件1和条件2都为真时执行的代码}else{// 当条件1或条件2为假时执行的代码} 判断字符串是否包含某个子串 代码语言:javascript 复制 if(str.indexOf('example')!==-1){// 当字符串包含子串'example'时执行的
// JavaScript代码示例letinput='B';if(input==='A'){console.log('处理条件A');}elseif(input==='B'){console.log('处理条件B');}elseif(input==='C'){console.log('处理条件C');}else{console.log('处理其他情况');} 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 对于Python或Bas...
JavaScript if...else StatementIn computer programming, the if...else statement is a conditional statement that executes a block of code only when a specific condition is met. For example,Suppose we need to assign different grades to students based on their scores....
从JDK 1.8 开始引入 Optional 类,在 JDK 9 时对 Optional 类进行了改进,增加了 ifPresentOrElse() 方法,我们可以借助它,来消除 if else 的判断,使用如下。 优化前代码: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 String str="java";if(str==null){System.out.println("Null");}else{System.out...
javascript 条件 if javascript if语句 javascript if语句 语法 if (condition) statement1 [else statement2] 1. 2. 3. 4. condition 值为真或假的表达式 statement1 当condition为真时执行的语句。可为任意语句,包括更深层的内部if语句。要执行多条语句,使用块语句({ … })将这些语句分组;若不想执行语句,...
<!-- /* *** Example if ...else and conditional operator*** */ var d = new Date(); var time= d.getHours(); if (time < 10) { document.write("Goodmorning"); } else document.write"Good day"); } //--> /script If youruntheabove it should...
Example If time is less than 10:00, create a "Good morning" greeting, if not, but time is less than 20:00, create a "Good day" greeting, otherwise a "Good evening": if(time <10) { greeting ="Good morning"; }elseif(time <20) { ...
} else { block of code to be executed if the condition1 is false and condition2 is false }Example If time is less than 10:00, create a "Good morning" greeting, if not, but time is less than 20:00, create a "Good day" greeting, otherwise a "Good evening": if (time < 10) {...
JavaScript var isRaining = false; if (isRaining) { alert("Don't forget an umbrella!"); } else { alert("No need for an umbrella."); } Live Example The moment we run the code, we get the second alert, just as we expected. Also notice the body of else. Just like that of if,...
在 JavaScript 文件中，我们可以使用各种方式来初始化数据项，例如从服务器获取数据、从本地缓存获取数据、从用户输入获取数据等等。通过使用 wx:if 和 wx:else 标签，我们可以方便地实现条件判断的 else 分支，从而增强小程序的可用性和交互性。3、wx:for 循环 WXML 模板中，可以使用 wx:for 列表渲染标签，实现...