js封装常用的工具方法大全

1.判断变量是否是空值（null、undefined、空字符串）：

function isEmpty(variable) {
  return variable === null || variable === undefined || variable === '';
}

2.判断变量的类型：

function getType(variable) {
  return Object.prototype.toString.call(variable).slice(8, -1).toLowerCase();
} 

function debounce(fn, delay) {
  let timer;
  return function (...args) {
    if (timer) clearTimeout(timer);
    timer = setTimeout(() => {
      fn.apply(this, args);
    }, delay);
  };
}

function throttle(fn, delay) {
  let timer;
  return function (...args) {
    if (!timer) {
      timer = setTimeout(() => {
        fn.apply(this, args);
        timer = null;
      }, delay);
    }
  };
}

function truncate(str, len, omission = '...') {
  if (str.length <= len) return str;
  return str.slice(0, len - omission.length) + omission;
}

function unique(array) {
  const result = [];
  for (let i = 0; i < array.length; i++) {
    if (result.indexOf(array[i]) === -1) result.push(array[i]);
  }
  return result;
}

function flatten(array) {
  return array.reduce((prev, curr) => {
    return prev.concat(Array.isArray(curr) ? flatten(curr) : curr);
  }, []);
}

function sortObjectProps(obj) {
  const keys = Object.keys(obj).sort((a, b) => a.localeCompare(b));
  const result = {};
  keys.forEach(key => (result[key] = obj[key]));
  return result;
}

function getScrollbarWidth() {
  const outer = document.createElement('div');
  outer.style.visibility = 'hidden';
  outer.style.overflow = 'scroll';
  outer.style.msOverflowStyle = 'scrollbar'; 
  document.body.appendChild(outer);
  const inner = document.createElement('div');
  outer.appendChild(inner);
  const scrollbarWidth = (outer.offsetWidth - inner.offsetWidth);
  outer.parentNode.removeChild(outer);
  return scrollbarWidth;
}

function deepClone(obj) {
  const type = getType(obj);
  if (type === 'object') {
    const cloneObj = {};
    for (let key in obj) {
      cloneObj[key] = deepClone(obj[key]);
    }
    return cloneObj;
  } else if (type === 'array') {
    const cloneArr = [];
    obj.forEach(item => {
      cloneArr.push(deepClone(item));
    });
    return cloneArr;
  } else {
    return obj;
  }
}

本文来自投稿，不代表站三界导航立场，如若转载，请注明出处：https://www.zhansanjie.com/article/details/41715.html