objects.forEach在Safari 9.0上不起作用

Question

我有此代码：

function fetchImage(url) {   /*return new Promise((resolve, reject) => {
    const image = new Image();
    image.src = url;
    image.onload = resolve;
    image.onerror = reject;   });*/   return new Promise(function(resolve, reject){   const image = new Image();   image.src = url;   image.onload = resolve;   image.onerror = reject;   }); }

function applySrc(el, src){   el.classList.add('loaded');   el.src = `${src}`; }

function applyBg(el, src){   el.classList.add('loaded');   el.style.backgroundImage = `url('${src}')`; }

const options3 = {   rootMargin: '200px',   threshold: 0.1 }

const callback_src = function(entries){   entries.forEach(function(entry){
      const ratio = entry.intersectionRatio;
      const element = entry.target;
      if(ratio > 0){
        observer.unobserve(element);
        const src = element.dataset.src
        fetchImage(src).then(function(){ 
          applySrc(element, src); 
        });
      }   }); }

const callback_bg = function(entries){   entries.forEach(function(entry){
      const ratio = entry.intersectionRatio;
      const element = entry.target;
      if(ratio > 0){
        observer.unobserve(element);
        const src = element.dataset.src
        fetchImage(src).then(function(){ 
          applyBg(element, src); 
        });
      }   }); }


const observer = new IntersectionObserver(callback_src, options3);

const observer2 = new IntersectionObserver(callback_bg, options3);

const targets = document.querySelectorAll('.intersection-observer-img');

const targets2 = document.querySelectorAll('.intersection-observer-bg');

targets.forEach(function(target){observer.observe(target)});

targets2.forEach(function(target){ observer2.observe(target)});

在Chrome，Safari 12，Firefox等上可以，但是在IE和Safari 9.0上不起作用。 问题似乎是 targets.forEach（function（target）{observer.observe（target）}）; ，因为错误是“ targets.forEach不是函数”。