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if 語(yǔ)句可以與 else 語(yǔ)句結(jié)合使用,在if中條件為 false 時(shí)執(zhí)行else中代碼
2)if......else if......else當(dāng)有多個(gè)條件需要判斷時(shí),可以使用 else if 進(jìn)行鏈?zhǔn)脚?/span>斷namespace _004_if語(yǔ)句{ public partial class if語(yǔ)句 : Form { public if語(yǔ)句() { InitializeComponent(); } //if else private void btIfElse_Click(object sender, EventArgs e) { int a = 10;int b=20; if (a>b) { MessageBox.Show("a>b"); } else { MessageBox.Show("a<b"); } } //if else if private void btIfElseif_Click(object sender, EventArgs e) { int week = int.Parse(this.txtWeek.Text);//將輸入內(nèi)容轉(zhuǎn)換為數(shù)值型 if(week==1) { MessageBox.Show("周1"); } else if(week == 2) { MessageBox.Show("周2"); } else if (week == 3) { MessageBox.Show("周3"); } else if(week==4) { MessageBox.Show("周4"); } else if (week == 5) { MessageBox.Show("周5"); } else if ((week==6) || (week == 7)) { MessageBox.Show("休息"); } } }}
用于根據(jù)一個(gè)變量的值執(zhí)行不同的代碼塊。namespace _005_switch_case語(yǔ)句{ public partial class Form1 : Form { public Form1() { InitializeComponent(); }
private void btswitch_Click(object sender, EventArgs e) { int a = int.Parse(this.txtWeek.Text);//輸入的數(shù)值 switch (a) { case 1://a=1時(shí) MessageBox.Show("周一"); break; case 2: MessageBox.Show("周二"); break; case 3: MessageBox.Show("周三"); break; case 4: MessageBox.Show("周四"); break; case 5: MessageBox.Show("周五"); break; case 6: MessageBox.Show("周六"); break; default: MessageBox.Show("周日"); break; } } }}
該文章在 2025/2/18 16:48:55 編輯過(guò)