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</head><body><script>const arr = ['red', 'blue', 'green']// 1.map方法 对数组进行处理并返回const newArr = arr.map(function (ele, index) {// console.log(ele)//数组元素// console.log(index)//数组索引号return ele + '颜色'})console.log(newArr)// 2.join方法 把数组转化为字符串// 小括号为空则元素之间用逗号隔开(默认)console.log(newArr.join())//red颜色,blue颜色,green颜色// 如果是空字符串则元素之间没有分隔号console.log(newArr.join(''))//red颜色blue颜色green颜色console.log(newArr.join('|'))//red颜色|blue颜色|green颜色</script>
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