function test(str){
    let arr = str.split("")
    let letter_low = arr.filter(i => i.charCodeAt() >= 97 && i.charCodeAt() <= 122).length
    let letter_up = arr.filter(i => i.charCodeAt() >= 65 && i.charCodeAt() <= 90).length
    let num = arr.filter(i => Number(i)).length
    let space = arr.filter(i => i == " ").length
    return `小写字母=${letter_low}大写字母=${letter_up}数字=${num}空格=${space}`
}