Regular Expressions All In One
Regular Expressions All In One
Regular Expressions Cheatsheet
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Cheatsheet
否定或补充字符集
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Groups_and_Ranges
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Assertions
Regular Expressions Cheatsheet
const log = console.log;
// a~z
const reg = /[a-z]/;
reg.test(`a`);
// true
reg.test(`z`);
// true
reg.test(`A`);
// false
reg.test(`Z`);
// false
js 模板引擎
js template engine
// templateEngine
const templateEngine = (str = ``, data = {}) => {
const reg = /{{([^{}]+)?}}/g;
let match, paths, key,template;
while (match = reg.exec(str)) {
console.log(`match`, match);
templateHolder = match[0];
// {{varibale}}
key = match[1];
// varibale
paths = key.split('.');
// ["k1", "k2"]
console.log(`paths`, paths);
let obj = data;
// 遍历多级属性
for (let i = 0; i < paths.length; i++) {
obj = obj[paths[i]];
}
// 模板替换
str = str.replace(template, obj);
}
return str;
}
const template = `<section><div>{{name}}</div><div>{{infos.city}}</div></section>`;
const data = {
name: 'xgqfrms',
infos:{
city: 'ufo',
}
}
templateEngine(template, data);
//"<section><div>xgqfrms</div><div>ufo</div></section>"
/*
match (2) ["{{name}}", "name", index: 14, input: "<section><div>{{name}}</div><div>{{infos.city}}</div></section>", groups: undefined]
paths ["name"]
match (2) ["{{infos.city}}", "infos.city", index: 33, input: "<section><div>{{name}}</div><div>{{infos.city}}</div></section>", groups: undefined]
paths (2) ["infos", "city"]
"<section><div>{{name}}</div><div>{{infos.city}}</div></section>"
*/
// const template = `<section><div>{{name}}</div><div>{{city}}</div></section>`;
// "<section><div>xgqfrms</div><div>undefined</div></section>"
js 金融数字格式化
千分位格式
const moneyFormat = num => {
const str = num.toString();
const len = str.length;
if (len <= 3) {
return str;
} else {
// 判断是否有小数, 截取小数部分
const decimals = str.indexOf('.') > -1 ? str.split('.')[1] : ``;
let foot = '';
if(decimals) {
foot = '.' + decimals;
}
let remainder = len % 3;
if (remainder > 0) {
// 不是 3 的整数倍, 有 head, 如(1234567.333 => 1, 234, 567.333)
const head = str.slice(0, remainder) + ',';
const body = str.slice(remainder, len).match(/\d{3}/g).join(',');
return head + body + foot;
// return str.slice(0, remainder) + ',' + str.slice(remainder, len).match(/\d{3}/g).join(',') + temp;
} else {
// 是 3 的整数倍, 无 head, 如(123456.333 => 123, 456.333)
const body = str.slice(0, len).match(/\d{3}/g).join(',');
return body + foot;
// return str.slice(0, len).match(/\d{3}/g).join(',') + temp;
}
}
}
// `123456`.slice(0, 6).match(/\d{3}/);
// ["123", index: 0, input: "123456", groups: undefined]
// regex match return ???
// `123456`.slice(0, 6).match(/\d{3}/g);
// ["123", "456"]
// regex match g return all grounds
moneyFormat(123456.33);
// '123,456.33'
moneyFormat(123.33);
// '123.33'
tools
Error
// space bug ❌
/{{([^{}]+)?}}/g
// 1 whitespace bug
OK
const regex = /{{([^{}]+)?}}/g
// no space ✅
{{([^{}]+)?}}
// no space ✅
/{{([^{}]+)?}}/g
/\{\{([^{}]+)?\}\}/g
demos
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refs
https://www.cnblogs.com/xgqfrms/p/13638168.html
Regular Expression 学习笔记
https://www.imooc.com/u/1066707/notepad/706
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