If

最简单的条件判断是if语句,语法是 if(condition){ do this … } 。条件判断为真,才执行分支中的代码。举个字符串的例子:

var country = 'France';
var weather;
var food;
var currency;

if(country === 'England') {
    weather = 'horrible';
    food = 'filling';
    currency = 'pound sterling';
}

if(country === 'France') {
    weather = 'nice';
    food = 'stunning, but hardly ever vegetarian';
    currency = 'funny, small and colourful';
}

if(country === 'Germany') {
    weather = 'average';
    food = 'wurst thing ever';
    currency = 'funny, small and colourful';
}

var message = 'this is ' + country + ', the weather is ' +
            weather + ', the food is ' + food + ' and the ' +
            'currency is ' + currency;

注意: 条件判断可以嵌套。

Exercise
Correct!
False!
填写 `name` 的值,验证条件判断。
var name = if (name === "John") { }