SOURCE

// 去除字符串两边的空格
const regForTrim = /^\s*|\s*$/g;

const spaceStr = '123 456 789   ';

console.log(`去除字符串两边的空格：${
    spaceStr.replace(regForTrim, '')
}`);

// 将每个单词的首字母转换为大写
const str = 'this is a dog';

const regForLocaleUpperCase = /(?:^|\s)(\w)/g;

console.log(`首字母转换为大写：${
    str.replace(regForLocaleUpperCase, match => match.toLocaleUpperCase())
}`)

// 驼峰化
const camelizeStr = 'moz transform';

const regForcamelize = /(?:^|\s|-|_)+(\w)/g;;

console.log(`驼峰化：${
    camelizeStr.replace(regForcamelize, (match, $1) => $1.toLocaleUpperCase())
}`)

// html转义和反转义
const escapeChars = {
    '¢': 'cent',
    '£': 'pound',
    '¥': 'yen',
    '€': 'euro',
    '©': 'copy',
    '®': 'reg',
    '<': 'lt',
    '>': 'gt',
    '"': 'quot',
    '&': 'amp',
    '\'': '#39'
};

const htmlEntities = Object.entries(escapeChars).reduce((pre, cur) => {
    const[left, right] = cur;
    pre[right] = left;
    return pre;
},
{})

const escapeHTML = (str) => {
    return str.replace(new RegExp('[' + Object.keys(escapeChars).join('') + ']', 'g'), (match) => `\$${
        escapeChars[match]
    };`)
}
const unescapeHTML = str => {
    return str.replace(/\$([^;]+);/g, (match, $1) => htmlEntities[$1])
}

console.log(`html转义：${escapeHTML('<div>¥</div>')}`);
console.log(`html反转义：${unescapeHTML('$lt;div$gt;$yen;$lt;/div$gt;')}`);