This JavaScript tutorial explains how to use the if-else statement with syntax and examples.Description In JavaScript, the if-else statement is used to execute code when a condition is TRUE, or execute different
“Function declarations should not be placed in blocks. Use a function expression or move the statement to the top of the outer function.”:“函数的声明不能放在类似if的块中,需要放在外部函数的顶部.” 针对自己项目中遇到的一些提示,做一些举例说明: 1 [W099]:Mixed spaces and tabs 这个错误是最常...
Finally, if no condition matches, the block of code in else is executed.Working of the if...else if...else statement Example 3: JavaScript if...else if Statementlet rating = 4; // rating of 2 or below is bad // rating of 4 or above is good // else, the rating is average if...
The if Statement Use theifstatement to specify a block of JavaScript code to be executed if a condition is true. Syntax if(condition) { //block of code to be executed if the condition is true } Note thatifis in lowercase letters. Uppercase letters (If or IF) will generate a JavaScript...
Some might contend that the JavaScript language itself is problematic. Indeed, it has its shortcomings, but it’s also ubiquitous—so it pays to understand how to navigate them if you (like most of today’s developers) have to work with some form of JavaScript code. ...
delete property; // legal only within a with statement objectName是一个对象名,property 是一个已经存在的属性,index是数组中的一个已经存在的键值的索引值。 第四行的形式只在with声明的状态下是合法的, 从对象中删除一个属性。 你能使用 delete 删除各种各样的隐式声明, 但是被var声明的除外。
JavaScript中的if else语句是一种条件语句,用于根据条件的真假来执行不同的代码块。它的基本语法如下: 代码语言:javascript 复制 if(条件){// 如果条件为真,执行这里的代码块}else{// 如果条件为假,执行这里的代码块} 在if else语句中,条件可以是任何可以求值为布尔值的表达式。如果条件为真,将执行if代码块中的...
// A conditional statement if (x === 0) { // Is `x` equal to zero? x = 123; } // Defining function `baz` with parameters `a` and `b` function baz(a, b) { return a + b; } 注意等号的两种不同用法: 单个等号(=)用于将一个值赋给一个变量。
// 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 `x` equal to zero?x=123;}// Defining function `baz` with parameters `a`...
You can define as many conditions as you need for your if statement, but keep in mind that too many conditions may cause confusion. Try to keep the conditions as minimum as you can. Finally, you can also pair the if statement with an else statement. ...