js 常用工具函数 节流函数 防抖函数 等

js获取url参数

  function getQueryVariable(variable) {
        var query = window.location.search.substring(1);
        var vars = query.split("&");
        for (var i = 0; i < vars.length; i++) {
            var pair = vars[i].split("=");
            if (pair[0] == variable) {
                return pair[1];
            }
        }
        return (false);
    }

截取字符串url中的参数

function getQueryVariable(url, variable) {
			let index = url.indexOf("?") + 1
			let str = url.substring(index)
			var vars = str.split("&");
			for (var i = 0; i < vars.length; i++) {
				var pair = vars[i].split("=");
				if (pair[0] == variable) {
					return pair[1];
				}
			}
			return (false);
		}

删除url中特定参数重新生成url

function createURl(url, variable) {
    let index = url.indexOf("?") + 1
    let str = url.substring(index)
    let newUrl = url.substring(0, index)
    var vars = str.split("&");
    for (var i = 0; i < vars.length; i++) {
        var pair = vars[i].split("=");
        if (pair[0] != variable) {
            if (/=/.test(newUrl)) {
                newUrl = newUrl + `&${vars[i]}`
            } else {
                newUrl += vars[i]
            }
        }
    }
    return newUrl
}

节流函数(绑定this)

export function throttle(callBack, time = 1000) {
	let timer;
	return function() {
		if (timer) return
		timer = setTimeout(() => {
			timer = null;
			callBack.apply(this)
		}, time)
	}
}

防抖函数(绑定this)

export function debounce(callBack, time = 1000) {
	let timer;
	return function() {
		if (timer) clearTimeout(timer)
		timer = setTimeout(() => {
			callBack.apply(this)
		}, time)
	}
}

防抖函数(绑定this,立即执行)

function debounce(func, wait, immediate) {

      var timeout, result;

      return function () {
        var context = this;
        var args = arguments;

        if (timeout) clearTimeout(timeout);
        if (immediate) {
          // 如果已经执行过，不再执行
          var callNow = !timeout;
          if (callNow) result = func.apply(context, args)
          timeout = setTimeout(function () {
            timeout = null;
          }, wait)
        }
        else {
          timeout = setTimeout(function () {
            func.apply(context, args)
          }, wait);
        }
        return result;
      }
    }

sass求百分比公式

// 百分比函数
@function percent($params, $params2) {
  @return ($params / $params2)*100%
}

// vw函数
@function vw($size) {
  @return ($size / $baseSize * 100)+vw
}

ios 上面禁止页面缩放

解释 为提升性能 很多浏览器将passive设置为true,这就导致preventDefault()无效
详细解释

window.onload = () => {
  document.addEventListener('touchstart', (event) => {
    if (event.touches.length > 1) {
       event.preventDefault();
    }
  }, { passive: false });
  
  let lastTouchEnd = 0;
  document.addEventListener('touchend', (event) => {
    const now = (new Date()).getTime();
    if (now - lastTouchEnd <= 300) {
      event.preventDefault();
    }
    lastTouchEnd = now;
  }, false);
}

微信h5网页关闭分享以及关闭当前页面

关闭网页分享一些按钮(开发者上可能会报错,请忽略,在手机上查看功能)

document.addEventListener("WeixinJSBridgeReady", function () {
    WeixinJSBridge.call('hideOptionMenu');
});

关闭网页

 WeixinJSBridge.call('closeWindow');