字符串转化成驼峰命名

    function convertToCamelCase (str) {
        var returnStr;
        if (str.charAt(0) === '-') {
            returnStr = str.substring(1).split('-')
        } else {
            returnStr = str.split('-')
        }
        console.log(returnStr)
        for (var i = 1; i<returnStr.length; i++) {
            returnStr[i] = returnStr[i][0].toUpperCase() + returnStr[i].substring(1)
        }
        return returnStr.join('')
    }
    console.log(convertToCamelCase('background-img-img2'))

　　方法二：

    function convertToCamelCase (str) {
        var returnStr = str.split('-');
        if (returnStr[0] === '') {
            returnStr.shift()
        }
        for (var i = 1; i<returnStr.length; i++) {
           if (returnStr[i] !== '') {
               returnStr[i] = returnStr[i][0].toUpperCase() + returnStr[i].substring(1)
           }
        }
        return returnStr.join('')
    }
    console.log(convertToCamelCase('-background-img-cas'))