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Array[数组]常用属性与方法
index:从0开始的数组下标;
length:数组长度;
prototype:数组原型属性;
数组常用方法
concat:连接数组;
示例: arr1 = [1,2,3]; arr2 = [4,5,6]; arr1.concat(arr2) = [1,2,3,4,5,6];
join():将数组转换为字符串,()里参数为连接字符,默认为",";
示例:arr1 = [‘a‘,‘b‘,‘c‘]; arr1.join() = a,b,c ; arr1.join(‘ ‘) = a b c; arr1.join(‘ + ‘) = a + b + c ;
pop():移除数组的最后一个元素
示例:arr1 = [1,2,3,4] arr1.pop() ==> arr1 = [1,2,3];arr1.pop()=4
push():将括号内元素追加到原数组后面
示例:arr1 = [1,2,3,4] arr1.push(3,2,1) ==> arr1 = [1,2,3,4,3,2,1];
reverse():倒序数组
示例:arr1 = [1,2,3] arr1.reverse() = [3,2,1];
shift():移除数组的第一个元素
示例:arr1=[‘a‘,‘b‘,‘c‘]; arr1.shift() ==> arr1 = [‘b‘,‘c‘];arr1.shift() = c;
unshift():将括号内元素添加到原数组前面
示例:arr1 = [1,2,3,4] arr1.unshift(3,2,1) ==> arr1 = [3,2,1,1,2,3,4];
splice( , ,..):移除数组里的元素==>第一个参数为起始下标,第二个参数为要移除元素的个数,第三个及以后参数为替换元素--取代被移除的元素
示例:arr1 = [1,2,3,4] arr1.slice(1,2);==>arr1 = [1,4] ; // arr1.slice(1,2,‘a‘,‘b‘);==>arr1 = [1,‘a‘,‘b‘,4];
slice(start,end):切割数组 start:开始下标 end:结束下标 结果 [start,end),原数组不发生变化
示例:arr1= [1,2,3,4] arr2 = arr1.slice(1,3) ==>arr1 = [1,2,3,4]; arr2 = [2,3];
toString():将数组转换为字符串格式,以","连接
示例:arr1 = [‘a‘,‘b‘,‘c‘]; arr1.toString() = a,b,c;
Array[数组]常用属性与方法