防抖与节流

节流

function throttle(fn, timer) {
    let time;
    return function() {
        if (time) return;

        time = setTimeout(() => {
            fn()
            time = null;
        }, timer)
    }
}

防抖

function debounce(fn, time) {
    let timer;
    return function() {
        clearTimeout(timer);
        timer = setTimeout(() => {
            fn();
        }, time)
    }
}

 节流第二种：

function throttle(fn, interval = 300) { 
  let canRun = true;
  return function () {
    if (!canRun) return;
    canRun = false;
    setTimeout(() => {
      fn.apply(this, arguments);
      canRun = true;
    }, interval);
  };
}

节流第三种：

var throttleV2 = function(action, delay){
    var statTime = 0;
    
    return function() {
        var currTime = +new Date();
        
        if (currTime - statTime > delay) {
            action.apply(this, arguments);
            statTime = currTime ;
        }
    }
}    

// example
function resizeHandler() {
    console.log("resize");
}

window.onresize = throttleV2(resizeHandler, 300);