[js functions] useful function for js #js

utils.js

// /userinfo/2144/id => ['/userinfo','/useinfo/2144,'/userindo/2144/id']
export function urlToList(url) {
  const urllist = url.split('/').filter(i => i);
  return urllist.map((urlItem, index) => {
    return `/${urllist.slice(0, index + 1).join('/')}`;
  });
}


// 极坐标转换成笛卡尔坐标
function polarToCartesian(centerX, centerY, radius, angleInDegrees) {
  let angleInRadians = (angleInDegrees - 90) * Math.PI / 180.0
  return {
    x: centerX + (radius * Math.cos(angleInRadians)),
    y: centerY + (radius * Math.sin(angleInRadians))
  }
}


// Radom key
const key = Math.random().toString(36).substring(7);


// 获取 URL 参数
const getURLParameters = url => (url.match(/([^?=&]+)(=([^&]*))/g) || [])
	 .reduce(
       (a, v) => ((a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1)), a),{}
     );

const getURLParameter = name => decodeURIComponent((new RegExp('[?|&]' + name + '=' + '([^&;]+?)(&|#|;|$)').exec(location.search) || [,''])[1].replace(/\+/g, '20%'))|| null;


// 获取 min-max 之间的随机整数
const randomIntFromInterval = (min,max) => Math.floor(Math.random()*(max-min+1)+min);


// 正则表达式，只能是数字和字母
const pattern =/^[A-Za-z0-9-_]+$/; 

// 根据window.devicePixelRatio获取像素比
function DPR() {
  if (window.devicePixelRatio && window.devicePixelRatio > 1) {
    return window.devicePixelRatio;
  }
  return 1;
}

// 将传入值转为整数
function parseValue(value) {
  return parseInt(value, 10);
};



function generateSmall(){
    var str = [];
    for(var i=97;i<123;i++){
        str.push(String.fromCharCode(i));
    }
    return str;
}

function generateBig(){
    var str = [];
    for(var i=65;i<91;i++){
        str.push(String.fromCharCode(i));
    }
    return str;
}

function isPercentage(n) {
  return typeof n === "string" && n.indexOf('%') != -1;
}

function convertToPercentage(n) {
    if (n <= 1) {
        n = (n * 100) + "%";
    }
    return n;
}