// Code to execute if condition is false } 在这个if-else语句中,如果“condition”是true,第一个代码块就会执行。如果“condition”是false,第二个代码块就会执行。 JavaScript还提供了if-else if语句,允许在多个条件之间进行选择。以下是一个示例if-else if语句: if (condition1) { // Code to execute if...
do…while 语句创建一个执行指定语句的循环,直到condition值为 false。在执行statement 后检测condition,所以指定的statement至少执行一次。简而言之 先执行代码部分然后再判断 statement 执行至少一次的语句,并在每次 condition 值为真时重新执行。想执行多行语句,可使用block语句({ … })包裹这些语句。 condition 循环中...
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// 使用 if/elseletresult;if(condition){result='value1';}else{result='value2';}// 使用三元运算符constresult=condition?'value1':'value2'; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 甚至可以链式使用,替代简单的 if/else if/else 结构: 复制 constdiscount=user.type==='premium'?0.2:user.ty...
In JavaScript, the if-else-if statement is used when you want to check more conditions if the given condition(s) is/are false. You can use else if to specify a new condition if the given condition is false. You can write as many else if statements to keep checking new conditions....
This JavaScript tutorial explains how to use the if-else statement with syntax and examples. In JavaScript, the if-else statement is used to execute code when a condition is TRUE, or execute different code if the condition evaluates to FALSE.
JavaScript includes three forms of if condition: if condition, if else condition and else if condition. The if condition must have conditional expression in brackets () followed by single statement or code block wrapped with . 'else if' statement must be placed after if condition. It can be ...
if (condition) { // Code to be executed if the condition is true } else { // Code to be executed if the condition is false } Table of Contents Introduction Importance Examples Importance of if else statement in JavaScript If-else statements in JavaScript are paramount, enabling conditional ...
The else statement is another conditional statement in JavaScript. Unlike if, it couldn't be specified alone — there has to be an if statement preceding an else. So what's else used for? The else statement executes a piece of code if the condition in the preceding if statement isn't me...
// Code to be executed if condition is false } The JavaScript code in the following example will output "Have a nice weekend!" if the current day is Friday, otherwise it will output the text "Have a nice day!".ExampleTry this code » let now = new Date(); let dayOfWeek = now....