es7 --- 新特性

 
                                                    
let arr = ['react', 'angular', 'vue'];
 
if (arr.indexOf('react') !== -1)
{
    console.log('React存在');
}
 
 

 
                                                    
let arr = ['react', 'angular', 'vue'];
 
if (arr.includes('react'))
{
    console.log('React存在');
}
 
 

 
                                                    
function calculateExponent(base, exponent)
{
    if (exponent === 1)
    {
        return base;
    }
    else
    {
        return base * calculateExponent(base, exponent - 1);
    }
}
 
console.log(calculateExponent(7, 3)); // 输出343
console.log(Math.pow(7, 3)); // 输出343
 
 

 
                                                    
console.log(7**3);